For those who have their iPod Touch or iPhones connected to their TVs through a third party video cable, the 3.0 update was a bad one. It appears to have disabled the ability of non-Apple cables to transmit video. Forum members at iPod Touch Fans and MacForums are both reporting the issue.
One forum member reports:
I have an AV Cable for my iPod Touch 1g which up until now worked fine. Then I updated to 3.0, jail-broke it fine and everything else seems ok, but the AV cable brings up the message about it not be
