This has randomly happened to me. Not sure why. Did you wipe before you flashed? Only time it happened to me was with a dirty flash.
Yes I had wiped because the time before, after just rooting/unlocking, I flashed PE and it just hung at the boot graphic for a half hour. so I did a batt pull and did a wipe and cache wipe before flashing again, and the rom worked. maybe I will try doing another backup and wipe this evening.
Does the new builds have any of the new 4.2 gapps in them? Like the new camera and gallery, etc
I am using the 4.2 gmail, camera, gallery and keyboard. All are working flawlessly as far as I can tell. Just grab the zips from the forums and flash them. I had to remove the stock gallery to get the 4.2 camera and gallery to work. On CM10 I could have both.