LS1B Operating System Upgrade Help

[fleshe]

Here's a small rundown of what I need help with. Along with the PCM files that will and won't run the car.

I'm currently working on a 93 LT1 Camaro that has the Torq-heads 24x Conversion kit. The PCM that has been wired to the car is a 12200411 with H/W Version 09386530.

I got the car to run on the factory 9381344 OS that came on the PCM by coping over all the calibrations from the 02 Chevy Express Tune that runs OS 12212156. I manually copied over all the compatible calibrations and the car starts and runs fine. Here's where I start to run into the problems. I want to upgrade to COS5 for Nitrous reasons. Since the 9381344 OS is not an upgradable OS I decided to Flash the PCM with the 02 Express Van tune I orginally copied all the calibrations from. The 02 Chevy Express van runs OS 12212156 which is a compatible OS with COS5 and it will allow me to copy over the calibrations I planned on adjusting before the COS5 upgrade to get the car somewhat on a decent tune. But, everytime I upgrade to OS 12212156 the car will not start. I have fuel but no spark. If I reload the 9381344 OS flash, the car will start and run just fine.

What am I doing wrong?