i don't know... i was on 1.1.1 and then upgraded to 1.1.4. then after i connected to iTunes it restored my phone from a backup i had so all my contacts where back as they were... did i do something wrong?
Are you jail broken? My phone had been freezing like yours as well as other strange artifacts like the iPod cutting in. I had reset the device many times to try and resolve. I went ahead and restored last night and recovered my backup info. No problems today.
My device was an OOTB 1.1.2 which I upgraded to 1.1.3 and now 1.1.4. My phone has not been jailbroken.
Another thought is whether you have one of the older production models that so many seem to be replacing. I am still on my first iPhone since 12/25.