Can somebody help me? After the download of the weather add-on, Firefox starts with a blank background and is completely freezed. Tried all known measures to patch. Reinstalled. Re downloaded the entire setup installer pack… nothing. Also scheduled and ran at reboot Avast!, A-Squared, MS AS Beta, AdAware etcetera. Ran HijackThis: online analysis ok. No new softwares installed or downloaded in the last 2 weeks. What happens? ???
Did you tried the Safe Mode feature of Firefox?
Ciao, Friend. 
Yes… nothing and nothing… I also have ran a CCleaner and a RegSeeker scan of the registry. Nothing appear strange.
Try to delete the Firefox profile…
Do you mean the folder in “C: Programs”?.. Done at the first time… Also deleted all the visible registry traces of Firefox.
IMPORTANT: actually I don’t have Firefox installed on my pc… eheheh… 
Hi Kamulko,
Try the following go to program files and to Mozilla FF,
take the shortcuts from the desktop, or start bar. Create new shortcuts and see what it does.
Second try: create a new profile at http://www.mozilla.org/support/firefox/profile#new
Another option is delete all
of Firefox, and reinstall from the setup program.
Before that save your profile files somewhere else, bookmarks.html cookies.txt hostperm.1 signons.txt & key3.db chrome\user\chrome.css & userContent.css, all this is copied WITH FIREFOX CLOSED
because else as you have noticed it overwrites all those files at shutdown.
Sure, you will FF soon after this, all is well that ends well,
Loads of success,
your friend polonus
I will try again: all traces of Firefox are deleted except the last setup package (I keep the setup of all my programs in my second HD). Thanks, Friend. I will say later the result.
Try the example of polonus 
On my system, the my profile is: “C:\Documents and Settings\x\Application Data\Mozilla\Firefox\Profiles\7x801q6o.default”
I’m here again: disconnected for repairs. Well, I tried your suggestions. Now Firefox is running… with my old setup of the 1.0.3 version :-. The 1.0.4 freeze the same as first. I don’t know the reason why this strange damage of the browser. The 1.0.3 is not secure.
Did you removed the previous profile?
Yes… I have used the same steps for the malware removal ;D
Added: now also 1.0.3 freezed!!! :o Maybe is the vengeance by Microsoft? ;D Is there a ghost in my machine?
Is better for you to report this problem on the Firefox forum…
Yes… maybe the 1.0.4 must be patched again eheheheh 8)
Your profile is in a different location.
C:\Documents and Settings\UserName\Application Data\Mozilla\Firefox\Profiles
Get ride of the lot and start from scratch, so uninstall, boot, delete everything from and including the Mozilla folder (it has a registry.dat file in there) in the above path. This will however mean your tweaks, settings, user prefs and extension info will be gone.
Thanks DavidR but In the first uninstall I’ve completely deleted all the traces (also these). Now the Firefox windows appears with blank background. The bars seems to be right but freezed. The strange thing is that the process is running. Plus, is possible to close the Firefox interface but the process firefox.exe remains active in the background and I must use the taskbar to kill it.
Hi Kamulko,
This sounds strange, scan with regedit, that you rename to _root_regedit.exe. This add-on you installed, must be some nastiness. Did you scan it thoroughly, did you analyze it with FileAlyzer? But acyually I can’t think you have done something wrong. It is just hard luck.
Greetings,
polonus