Sometimes a complete wipe is needed...
Sometimes when moving from one ROM to another a complete wipe and format of all partitions (except sdcard) is needed in order for it to work. Have you wiped and formatted all your partitions before flashing the ROM? I use Titanium pro to backup my apps before doing this.
You should be able to do this with any of the recovery programs. 4EXT is really good and easy to use for this. Also, if you don't already know this, you should flash the correct GAPPS for your ROM after you install the update. That way you will have everything you need on your first boot after your flash.