There seems to be a rendering problem with the version of your browser being offered for download at the moment (13/06/01) I'm testing it with javascript/CSS heavy pages and find when generating a layer on the fly, then giving it a background image, the parts that are supposed to by transparent are being rendered opaque black. Also, the javascript pop-up window has scrollbars for some reason.

Apart from these points it's pretty fast! Not as quick as IE5, but faster than NS6 at moving layers around the screen. Nice work!

If you would like to see the problem, please go to the following page and click the "Sprite example 4" link from the list on the left:

http://www.javascript-games.org/gamelib/

Make sure that you're using W3C compliant code. Otherwise, just a guess, but it could be related to Mozilla bug#77914:

http://bugzilla.mozilla.org/show_bug.cgi?id=77914

I don't think there's a problem with the code; everything is setup using the DOM, not html and the problem doesn't manifest itself with NS6 or Mozilla 0.9.

There's another example related to CSS and background image:
http://www.kukka.net