Just really a bit of a information post continuing on from Here
I had a Defy floating around here - that was not getting any love (since my phone - at the time was a Samsung Galaxy S) - I loaded it up with Cyanogenmod and then gave it to one of my friends from Uni (who had a outdated HTC Magic running on 2 Degrees who really needed a upgrade)
When we popped the sim into the phone, it would not connect to the network at all, since I did mess with it a bit I decided it might be worth attempting to restore the phone which still didn't change the end outcome. I ended up shoving the sim into my Xoom which weirdly had the same issue and wouldn't connect to the network at all while my SGS + his Magic worked no problems.
We decided to go walkies to the 2* store to do a sim swap to a newer version, in my experience I have found the problem can be caused by a outdated STK or just the sim itself not working right - I knew for a fact my mate had been using the sim since day one of the 2* launch.
2 minutes later, $5 spent, we popped the sim into the Defy (running again with Cyanogenmod) and it worked as good as gold. I don't know how a older sim would have caused this but hopefully somebody on Geekzone can give me some info on this. If you are experiencing huge problems in your Motorola device it might be worth looking at the sim - this is often overlooked with the customer often sending the phone away for repair thinking it's the phone itself.