I've got a Vortech blower on my car with a custom SCT tune. Got about 6k miles on since the custom tune and every once in a while I get the same thing. As a matter of fact it happened today, car normally runs absolutely perfect idles right at about 850 with absolute stock drivability but like today it will start and barely run. It idled at about 400 and even died a couple of times unless i gassed it to keep it at 1k. I'll have to check for vacuum leaks, which is what is a common problem as others have stated.
Vacuum leaks are a complete bitch to find sometimes, get a pressure tester and hook that baby up.
Sid3ways--thanks for that info cuz i am sure mine has to do with vacuum leaks and a little to do with the tune. I will defiantly look for some vacuum leaks.