wrxtuner:
Don't know about others, but this is why I usually add my custom OEM's one at a time. All I can suggest is post the custom OEM's you are using and see if anyone here has encountered problems with one of them in the past. Otherwise when I get that error I usually go back and try removing the newly added OEM's one by one. Next time you may be better off installing your new custom OEM's one at a time so you can locate the problems. I find it will save more time in the long run.
In fact I just had that problem yesterday with the Facebook app that I OEM'd, since I flash one at a time (don't go through the entire process, just flash see if it makes it to setup screen and then add the next one) I knew what the issue was almost right away.
In the past I have spent hours trying to fix custom OEM problems. Taking 5 minutes to test a single OEM seems like a lot, but when you spend hours trying to fix problems afterwords, you will be more than thankful you did.