iPhone FW 3.1 blocks tethering. WTF?!

This week Apple released its version 3.1 of the iPhone firmware. Unfortnately I upgraded and realized that internet sharing via iPhone (tethering) has been blocked by now. Wow...
I have to admit I feel kinda pissed cause usually I wait with upgrades because I don't want to find myself missing a feature and here I am... Damn it... :-(

PS: T-Mobile Germany now offers a tethering option for clients who have signed a contract for only 20€/month more. Needless to say that I am waiting for some kind of hacked firmware because I don't see myself paying for something that has already been working fine and is no kind of real extra feature... Grrr...