Over on ccleaner forums i was reading this.
http://forum.piriform.com/index.php?showtopic=22766
Just thought it may be of interest.
pete
Thanks Pete. I still using FF 3.0. I try to figure out the feedback from 3.5 users one by one to have a better understanding first before switching to 3.5. 
Firefox rocks ;D
So the bottom line is, Do not touch anything if u do not know wat ur doing^^ ;D
BTW FF rocks^^The best eva!^^ ;D
-AnimeLover^^
Yup =)
I have FF 3.5 for weeks now. A lot of crashes >.> and can’t close last tabs.
But the new features are nice. I’m not gonna delete everything everytime I close FF though 
OK I have tried 3.5 for 5 hours and decide to reinstall 3.0.11. Unhappy experience here :-\
First after I install 3.5, it cannot connect to internet. My Vista 2GB system hang and need to restart.
After restart, everything back to normal. Surf net, check for addon update. No problem until … I go for dinner and close Firefox. After dinner, when I back, I start my firefox and it said : Firefox is currently running … (I have closed it). I open Task Manager, yes the firefox.exe is under the Process running. I click it and click End Process and it won’t allow me to do so. I used Chrome to search Firefox support forum and yes a lot of same issue there.
I restart my PC and can use firefox back. Purposely close it and try to restart the firefox and same problem happen. Meaning everytime if I close Firefox, i need to restart my PC if I want to use firefox again ! >:(
No choice. I love my FF. So I reinstall back 3.0.11. Everything back to normal.
FF 3.5 still need time : But I can wait. ;D
Well I installed it yesterday using the Help, Check for updates. It told me what add-ons wouldn’t work in 3.5 and since none were security or important to me I proceeded. The update went fine I hacked 3 add-ons to get them to work and all seemed to be working fine.
When I started today I had a bit of a weird occurrence as it tried to load several of my previously viewed pages/bookmarks. I killed those and disabled one of the hacked add-ons, Tab-Mix which I believe was the problem and restarted firefox and things have progressed normally.
Pages seem to be loading a little slower today, yesterday it was much faster loading than normal, but my dial-up has been very flaky over the last week.
So for me 3.5 hasn’t been an issue really. The subject of this topic shouldn’t be an issue either if you have left things at the default settings.
Hi
I’ve Updated My - Firefox 3 … To … Firefox 3.5
Laptop - Updated yesterday afternoon … No Problem! 
Desktop - Updated this morning … One Mini Problem! :-\
Basically!
The icons for Firefox on my side of the computer changed to the new shiny 3.5 ones.
But on my sons side of the computer… They all remained the old v3 dull ones :
In The End!
The only way I could get a Shiny New Firefox Icon for my little lad…
Desktop Icon
1/ Right Click
2/ Properties
3/ Change Icon
4/ I Found The Correct Shiny Icon For Firefox 3.5 Just Waiting For Me ;D
Quick Launch Icon
1/ Deleted the old button
2/ Made a new button from right clicking the the new Desktop icon - & - Add To Quick Launch
Re : Firefox - Location Aware Browsing - Security Concerns 
Some Links For You All…
http://www.howtogeek.com/howto/1672/deactivate-location-aware-browsing-in-firefox-3.5/
http://www.mozilla.com/en-US/firefox/geolocation/
I Think It’s Awful >:(
What do all you guys think?
Sorry!
Just had to change that last number 2 - Made a Mistake! :-[
We’re havin a Heatwave here in the UK … & … It’s Killin Me!
I Can’t Consentrate On Anything!
I Love Hot Weather!
But this is ridiculous … I feel like I’m melting 
Thank you for the heads-up regarding the action of checking Site Preferences. It is unchecked by default. Its action is documented at http://support.mozilla.com/en-US/kb/Clear+Recent+History#What_is_history_
I updated to Fx 3.5 yesterday using Help > Check for updates. The updater found a compatible version for most of the 59 extensions I use. Most of the others still work if I set the about:config pref extensions.checkCompatibility to false. These were the exceptions:
- Digger doesn’t work. It was only a minor convenience anyhow. I haven’t bothered looking for a replacement.
- Tab Mix Plus. Replaced the official release version, Tab Mix Plus 0.3.7.3, with the development version, which works on Fx 3.5. Available at http://tmp.garyr.net/forum/viewtopic.php?t=9864
I haven’t had any problems. Fx 3.5 seems to be as rock-solid as Fx 3.0.11. Most of the changes are “under the hood” as they say. They’ve been thoroughly tested during its long public development, which has been going on for over a year. If you have any problems with it, most likely there’s something wrong with your configuration: often your firewall or incompatible extensions and themes. It’s not going to get much “better” before the next major release, Fx 3.6, which may not be ready until 2010. Many of the few people that have had any problems have had success fixing things up by asking for help in one of the Firefox support forums:
http://support.mozilla.com
http://forums.mozillazine.org/viewforum.php?f=38
@ Hally
I don’t use desktop icons, they are always hidden, I either use the Quick Launch area in XP Pro or RocketDock to launch applications.
So I have never seen the difference in firefox desktop icons.
Location-aware-browsing was the first to deactivate here.
Short Description:
about:config, then geo.enabled to false.
That’s it.
Just to add 1: Heatwave here in Norway, too. Let’s enjoy it while we can.
Just to add 2: I find FF 3.5 much quicker than 3.0, but Opera continues to be my first choice, I think…
Regards
HL
Hi Dave
The new Firefox icon is much brighter, lighter, and looks really shiny compared to the old one 8)
Thanks!
Hi hlecter
1 : I am trying to enjoy it while it lasts.
But today it’s - Crazy Hot! :-[
2 : Yeah! … I’ve noticed FF 3.5 is way more faster than the old FF 3 8)
Yeah, on my XP, the only logo that I can’t get to change is the start menu shortcut, the one where Firefox is set as my default browser, not the one that is under start menu → all programs.
Hi Go Pack Go
I’ve still got IE8 as my default browser on both my laptop and desktop computer.
Laptop … One User - Me!
Desktop … Two Users - Me & My Son!
However!
It was only the Firefox 3.5 icons on my sons side of the desktop computer that I had problems with ???
All Of Them! :
Desktop … Now Fixed! 8)
Quick Launch … Now Fixed!
Start Menu … Like You! - Still NOT Fixed!
All Programs / Firefox Folder … Still Not Fixed!
Me too. I’ll wait until 99% of my extensions get updated… I had a mess with 3.5.
MozBackup save my day (again).
Dare to try … install FF3.5 again. ;D
Same problem >:(
So I uninstall again … :-\
No no no this time I do not uninstall FF3.5, try other things. 
I uninstall my ZAF and restart my PC …
It works ! :o And now I can enjoy my FF3.5 :-*
Now need to look for a new firewall
Online Armour
PCTools
Outpost Firewall Free
Comodo
Personal Firewall Tests & Results. Firewall rating:
http://www.matousec.com/projects/firewall-challenge/results.php
About the leak tests limitations: http://forum.avast.com/index.php?topic=29259.msg247460#msg247460
Thanks Tech.
I see many people advertise PC Tools Firewall Plus, so I give it a try now. Some users rated Comodo made them mad so it will be my last choice.
PC Tools have a nice GUI. Choose Normal User mode. No FF problem at the moment. Thanks.
No wonder I never see ZA even mentioned in this forum since I joined.
Just installed Firefox 3.5. (Out of Beta, now.)
No problems.
The Location Aware Browsing feature does not bother me; it is not a gaping security hole, as some are suggesting on some sites. For the information to be passed requires a specific user allowance.
I only have a handful of add-ons; they seem to be working OK.
Well, I did not mention as you’ve already uninstall it.
ZA and Comodo has, from time to time, their issues with avast.