You'll want to stay on the 3.0.1 FW, not revert back to 3.0. 3.0 has a SMS vulnerability. You did the right thing by updating. You use the 3.0 IPSW, but you stay on FW 3.0.1 (this works because there is very little difference between 3.0 and 3.0.1). I listed all the steps here.
http://www.everythingicafe.com/forum...elp-52430.html