Comment 18 for bug 223238

I spent the better part of an afternoon fighting this problem (or one much like it) on my laptop. Free nv driver works, but the restricted driver causes really obnoxious stalls, to the point where the app dims out multiple times for several seconds on some pages.

Page which demonstrates the behavior most severely (ironically):
http://mozillalinks.org/wp/2008/02/firefox-3-ultimate-feature-performance/

I saved a local copy of the CSS, and did a binary search to find the offending CSS. Here it is:
#page {
 background: url(images/structure/backgroundColumns.png) repeat-y;
 background-position: 3px;
 margin-top: 50px;
 width: 970px;
 margin-left: auto;
 margin-right: auto;
 border: 1px solid #D9D9D9;
 z-index: 10;
 }

Readding pretty much anything on the #page entity causes rendering stalls. I started readding individual lines from this chunk, but there didn't seem to be one particular culprit. It seems that most/all of these lines contribute to the sluggishness somehow, to varying degrees.