- Are you on Windows-7? And, could you tell us which version of FireFox are you using?
And yes, there are some compatibility issues with some particular version of browsers with our software, and sometimes they issue "fix" patches, but not all the time.
I actually had a similar problem of "disappearing cursor" when I was on the last version of Opera, and it happened only sometimes also. Clearing cache and restarting the computer usually helped when I encountered this problem. Since then, the version of Opera on my computer was updated and so far I haven't encountered the similar problem yet, but I haven't had a much chance to use the newest version of Opera so far since the last version update, as I have been mostly using FireFox for a while, and no, I do not seem to get that problem on this version of FireFox (currently using 3.6.10.)
Let me know if clearing cache and restarting computer helps (it may or may not, but I think it's worth trying.