Music Upload Problems

Has anyone else had this problem? Whenever I go to upload a music file (ex.:
mp3, wav) to the internet (in this case Yahoo! Groups), it won't go. If I
use IE6, it gives me the "Page Cannot Be Found" page. If I use Netscape, it
gives me a "Document Contains No Data" error.

This problem started around the time I finally managed to get the SP2
download to work and install on my computer. I think it was around that same
time that I got Media Player 10.... My sister, who has the same setup as I
(XP SP2 & MP10) has the same problem.

When I upload the file using a computer that has W2k and MP9, it goes just
fine. Any ideas?

I'm using McAfee for my firewall and virus protection, so I don't think it's
the built in firewall or other Microsoft security items causing the problem.
I've also tried turning my Mcafee off during upload attempts, so I've
confirmed it's not them either. I'm stumped and a little frustrated. Any
help would be greatly appreciated!

Thanks!
Raya