The following news just got in.

The few coders that have been accepted into Apple’s iPhone Developer program are now reporting that the 1.2 beta firmware will lockup your device if you’re not constantly updating it to the latest release.

The problem is, that the new firmware also upgrades the Baseband software.

And by doing this, the firmware seems to lock all phone call options if you do not upgrade frequently.
It also appears that when you have upgraded the Baseband, it’s no longer possible to downgrade !

There are rumors in the hacking community that there are already patches available, but these haven’t been made public yet.

So for all of you who like to play around with the new firmware, i advice you to be very careful.