My pleasure. Please let us know what answer you receive. 
I certainly will. If and when…
Best regards.
Do a repair and remove the plugin for browser protection.
I don’t have the plugin installed.
Thanks.
There is a way to see where the extra memory is coming from. Firefox has memory meassuring capabilities, to access it open a new tab and type in the address bar “about:memory” click meassure and it will create a memory report which will show how Firefox is using memory. If there is a difference of 20MB with latest version of Avast! about:memory should be able to see where that extra 20MB is coming from.
Creating about:memory reports of Firefox without Avast! installed and with Avast! installed will really help. I won’t be able to read the reports but the people at Mozilla will be able to. If Avast support is unable to help, I suggest filing a bug report on Bugzilla.mozilla.org with “memshink” in the Whiteboard, this will get the attention of the mozilla developers that deal will memory usage issues.
Hope this helps.
Hi ItNoWork,
That’s a good idea. Thank you.
I’ve uninstalled and reinstalled Avast a few times during the last three days (quite a headache).
I’m currently trying Panda AV, and I’d rather wait for an explanation From Avast team before installing it again.
I’m not sure about filing a bug in Mozilla; the problem seems to be in Avast new version.
Best regards.
Problem is you interpretation. I personally don’t see a problem at all.
No two version ever have the same MB usage unless there hasn’t been any change.
Even without change, there are many other factor that weight into this situation none of which may be Avast related.
I agree with Bob.
I don’t also see no problem at all.
Yaron, what you are doing is saying e.g.
1000 km + 1 mm is more than 1000 km.
But do you really notice a difference when walking both distances ?
I bet you don’t.
Martin and Lukas (Avast team) have contacted me. Thank you both.
I’ll update later.
Hello all,
I’ve just sent the following lines to Lukas.
I think I’ve found the explanation:
I use Roboform which (in a certain configuration) does not attach to Firefox 39.
I’ve changed (with Resource Hacker FX) the version in firefox.exe from 39 to 38, and thus Roboform works properly.
Prior to v2223, Avast wouldn’t try to prevent the change, and also there was no difference between running the the original firefox.exe and the new modified one.
With v2223 , Avast tried to prevent the change (I chose to exclude). Also, when running the new modified firefox.exe - it consumes an extra 20 MB on start-up.
Interestingly - adding “firefox.exe” to Settings → Exceptions, solved the problem (no extra 20 MB) for that session; but after reboot it’s there again: a difference between the original file to the modified one.
I’d be grateful for a solution.
(I’d be glad to send you the dump files if you still think it might help).
Best regards.
Continued here.