In response to some of the earlier posts in this thread about boot loops, try this it worked for me:
I had Modaco 3.1 with a EXT3 partition on my SD card, working for ages. I updated to EXT4 without changing anything else and got boot loops. I tried a few things without wiping or restoring and found that the only thing that worked was to do another upgrade ext2 to ext3. For some reason it then loaded and my apps work fine. Also, my phone is now rediculously fat, although that might be because I updated to MCR3.2b3 (afterwards).
Today I picked up my phone and left the house. Only to find that I didn't have it half way to work. Tracked it down on Wavesecure. It was close by the house (how it got there I'm not sure). Anyways, I got it to lock with a message (saying ring my housemate) and a wail. A builder found it and it is returned and safe.
Signed up for Ad free lase night and baked me a rom.