Get all sites to work with Firefox

I have troublke with some sites when I try to load a video or even just the homepage of certain sites.

EX: I was trying to load a yahoo music video (Bodies - Drowning Pool)

and when the site came up it said that it can’t detect Netscape 4.7 or higher even though I have the most recent version of it.

I tried the exact same thing on INternet Explorer and it worked.

So, how can I get the videos to work on Firefox?