that's what I had feared.... some servers can't handle the rainbow function... it really depends on the server, not the browser or anything else.
I guess I'll have to rewrite it. If you open up your javascript console, is the error around this peice of code...
the error occurs because on some servers, vBulletin seems to double the number of modulus mathematics functions (% / the percent sign) in a phrase. I don't know why vB does this, or why it occurs onlly on some servers. That peice of code originally looks like this %360 (only 1 %)