It's a different kernel in the new builds. I restored the memory allocations back to Qualcomm defaults. There's been reports on other msm7x27a devices that this might have caused reboots for some users.
This happened to me, too. When I was using my phone, the screen sometimes flashed with blue colour and rebooted, but since I intalled this new build, it didn't reboot yet. So, I think this solved this problem. Awesome.