I have flashed my ATT MPX220 (formerly v0.343) with this v1.39 with no errors. Interesting that this ROM made it out before the Cingular one - and they had a sign up page to get Cingulars... I can't find any official writeups on Moto's site to see what was patched/changed withthis update.
Its only been 2 hours since I flashed and Sysinfo is showing a bit (like 50k) more overhead free at powerup than I had before. But, that could be a misnomer since I load and unload stuff all the time trying them out. I may have had a stub of some old programs left under the old ROM image.
Earpiece volume is much better and speakerphone is louder as well.
I've reloaded all my apps now and am interested to see if memory management and all the leaks are plugged. I'll report back in a couple of days.
Downside: you still can't use your BT headset for voice commands! I don't remember for sure but I understood this was a manufacturer (Motorola) not a carrier (Cingular/AT&T) or MS OS stack problem. Anyone know who I should be damning everyday as I hold up my phone in the car for voice commands?
Oh and, it's still WM9.