Moving Mouse over Mozilla causes 100% CPU

Joe Bruin · Post by **Joe Bruin** » January 9th, 2004, 7:41 am

Hello,

Has anyone experienced this problem on a Windows 2000 Pro, SP4 (or on any Windows version actually):

After exiting AOL 8.0 or 9.0 (you must actually log into AOL first, problem will not appear if you did not sign into AOL), and you open up Mozilla, Netscape, Firebird, or Thunderbird (let's collectively call of these apps "Mozilla"), the CPU goes up to 100% every time you move your mouse while the Mozilla window is on top. Usually the CPU ranges from 50% to 100% and would hit 100% as the mouse moves from a specific area in the app (say a JPEG image on an HTML file) over to some other area (say an empty space or text). With this problem, Mozilla's performance sometimes would go down dramatically and up to the point that the application is not usable.

Fortunately, I also found a workaround to this strange problem, which is by loading IE and loading a webpage in it. IE seems to "reset" this "bug" and the problem disappears.

So I guess my question is (perhaps aimed at the Mozilla developers), Is this an AOL, IE, or Mozilla bug? This strange behavior does not reproduce in any other app or browser (eg. Opera) after AOL exits. My guess is that AOL, IE, and Mozilla use a shared component and either:
1) AOL failed to reset the shared component before exiting
2) Mozilla doesn't initialize the shared component correctly

I've had this "bug" since I was using Netscape 7.0 first release. At the time however, I thought it was a Windows problem and restarting Windows seemed to fix it. However, after time, I realized that this problem occur between only AOL and Mozilla, and can only be reproduced by means described above.

Currently, this is what I have in my system (with respect to this problem):
- Win2k SP4
- Firebird 0.7 (Milestone Release)
- Thunderbird 0.4 (Milestone Release)
- AOL 8.0, 9.0
- IE 6.0.2800.1106

dacovale · Post by **dacovale** » January 10th, 2004, 4:49 am

This is an interresting phenomena.
But since I don't have either W2k or AOL....
I'd advice you to post this in the bugs-forum in here on Mozillazine (don't matter which one in this case, as long as you don't crosspost it to both)
The readers there would be more used to checking up on such things.

Joe Bruin · Post by **Joe Bruin** » January 11th, 2004, 5:50 pm

Ok ... will repost in the Bugs Forum ...

Thanks for getting back to me.