Its on the bottom...wayyyy bottom...says "powered by vBulletin" strangely its in gray and the gray doesnt show well in the blue so i dont blame ya if you didnt see it
I quite like PHPBB actually.. and I think it's updated to fix these flaws that are exposed a bit quicker than VB...
I think online software (especially PHPBB) really benefits from the open source movement, and the hundreds of bug fixers, especially when compared to the relativly small VB team...