It's all very slick looking, but a couple of things.
1. some things are blue. (ie registration page, posting a topic, the user cp) it kinda clashes...
2. the smileys. phpbb smileys (for some strange reason) don't use transparency correctly, so you get those little white corners on some of them...
3. general discussion forum doesn't have a new post button.
other than that, awesome site! so glad to have a good-looking and working forum finally