Cannot download to FF 3.6.6 (Win XP)

[Dave]

I may have correctly installed fonts on Win XP system; not sure where to pur other StIX folders. That said, I am unable to download firemath, no matter how far back I go in versions. I get a persistent drop-box informing that firemath requires FF 3.6 - upgrade FF. Heck, I'm at 3.6.6.

Is this no longer maintained? Any other recommendations?

TIA - D