I tried steve's build when it was in it's infancy and got an error when I'd try to enable the wifi in the menu - all it would do is say "error" below it. I switched to the stock o2 2.2 rom when it was released, and this fixed the error.
After getting fed up with the lagginess of the o2 build, I followed the instructions and swithed to steve's 1.6.1, hoping it would be solved. Sadly, the problem remains and I'm not sure what's wrong. Everything else seems fine, it's just the wifi that's screwed up.