See http://frankyan.com/labs/orientation.html. Not only do I get lots of checker boarding, but the web page is also cut off to the left, rather than having the text wrap like on the desktop. Bug 635330 might be related.
Created attachment 517577 [details] Screenshot Mozilla/5.0 (Android; Linux armv71; rv2.0b13pre) Gecko/20110307 Firefox/4.0b13pre Fennec/4.0b6pre Device: Droid 2 OS: Android 2.2
Perhaps this would improve with the patch in bug 640997?