I have a Flash website that I have tested in various browsers on my laptop, and it looks fine.

I tested it on another PC in Firefox 3.6.8 (same version as my laptop) but for some reason, there is a sprite missing from the stage. On the same PC, the website looks fine in IE8.

The vanishing sprite aside, the whole site is kind of sluggish in Firefox. The PC is kind of slow and old, but I can't see why that would cause images to vanish.

Any ideas?