Of 20+ windows I've got open right now, only 3 have window titles that are not 'OmniWeb'. They were all opened automatically at startup, and I've tried reloading a few to see if that would fix it. One example is:
http://www.faqs.org/rfcs/rfc3161.html
This is w/ 10.4.6 PPC, OW 5.5 SP6
http://www.faqs.org/rfcs/rfc3161.html
This is w/ 10.4.6 PPC, OW 5.5 SP6