I had 1.1.2 (1.1.1OOB) phone. Restored to original Apple 1.1.4, then used Pwnage to build custom fw image. Phone is unlocked, everything works, except Wifi. It won't work on any Wifi network more then 5-10 seconds, disconnects immediately. That is, when there is no traffic. It's not gray wifi problem. Tried Wifi fix, but it said 'nothing to fix'.
One more thing: Just before restoring to custom pwned fw, when I connect iphone to computer, iTunes goes to Activation screen, so I can't restore in normal mode, but have to do it from Restore mode. Is this normal? Could this be a reason for the Wifi problem?