Old thread, but thought it worthy of an update.

I had the stock PCM reflashed to the updated code mentioned in the TSB. It's now been months, and not a single problem since, so this fixed it for sure. Even better, the car now feels as strong as my old 99 did. I always felt I lost some power when I traded my 99 GT for this 05 GT, and now I've got my missing power back too.

Happy New Year folks.