The scrolling on littlebigplanet.com lags very bad. The problem resides on the box-shadow property applied on the body I think. If with the developer I disable the property, firefox stops lagging. It lags on the current Firefox 18 and the nightly, smooth scrolling on/off and with D2D accell on/off. On chrome,IE9 and opera it works very smoothly. Maybe firefox render continously the shadow...

Confirmed the problem in Firefox3.5-Nightly21.0a1. And also confirmed the following xss helps: body { box-shadow: none !important; -moz-box-shadow: none !important; }

Regression window: Good: http://hg.mozilla.org/mozilla-central/rev/5f349409c9d5 Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2a1pre) Gecko/20090209 Firefox/3.2a1pre ID:20090209105101 Bad: http://hg.mozilla.org/mozilla-central/rev/2681688f4cdf Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2a1pre) Gecko/20090210 Firefox/3.2a1pre ID:20090210050102 Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=5f349409c9d5&tochange=2681688f4cdf Suspected : Bug 476738