I too am having problems after the 2.2 update. 3G problems. I used to always be on 3g, with a pretty strong signal too, but after the update it's always on edge and only has 1 or 2 bars.
I tried downgrading to 2.1 last night, and it kept giving me to 1013 error, so I restored it with 2.2.
The instructions say to ignore the 1013 error when you are downgrading, but how? After it gave me the error and said my restore to 2.1 couldn't be completed, it put the iphone into recovery mode automatically and forced me to restore again. I knew it wouldn't work with the 2.1 file as I had already attempted it 3 times and each one ended with the 1013 error, so I just restored to 2.2.

I tried downgrading to 2.1 last night, and it kept giving me to 1013 error, so I restored it with 2.2.
The instructions say to ignore the 1013 error when you are downgrading, but how? After it gave me the error and said my restore to 2.1 couldn't be completed, it put the iphone into recovery mode automatically and forced me to restore again. I knew it wouldn't work with the 2.1 file as I had already attempted it 3 times and each one ended with the 1013 error, so I just restored to 2.2.