Upgraded to 3.0 and now cant respond to texts iPhone

sounds like the OS did not install properly. back up, reset to factory.
iBook G4, Macbook Pro 2.5Gz, iPhone 3g, Windows XP SP2 and SP3, Windows Vista Mac OS X (10.5.7)

Ive got the same issue on two different iPhones. Mine, an original 8GB version and my wifws, a newer 3G. I downloaded and installed 3.0 OS last night on mine and did same this morning for my wifes phone......both have the same issue....cannot initiate or respond to test messages....have to clear previous conversations before the keyboard allows message typing and sending....hard to agree with assessment that I need to retore to factory and reload on both sets because it didnt load properly the first time....a little too coincidental but Ill give it a try.
iPhone OS 3.0

I had this problem also... but what I found is that you have to tap on the box that your text msg. prints in to bring up the keyboard. You use to tap on the send button to bring up the keyboard. Its working fine for me now.
Mac Book Pro Mac OS X (10.5.6)