I'm seeing this too, from the customer site I'm at, but it wasn't doing it at home this morning. Pictures are red X's, and going to photobucket gets me a site called atspace.com. Looking into it, since this is basically what I do, fix computer weirdness.
Pinging photobucket.com from this location gives me an address on the same network with atspace, pinging it from work gives me a completely different address. Looking for hijacks or DNS goofiness. The fact that the ping is incorrect pretty much rules out IE vs Firefox. Hosts file is correct, no fake photobucket entries.
I hate it when people make me work for a living!
Changed my settings to use a different DNS server, and it works correctly. Resetting the customer's internal DNS server. . . . .
After restart of internal DNS servers, photobucket works again.
DNS problem somehow, but I never actually found where it came from.