PT9 Issue - Tracks move out of alignment in Playback

[Beau_McKee]

Hi there
I'm having some serious issues on a session in PT9. I successfully bounced a great Mix i did. I then saved the session, closed for a few days, then reopened it. But after opening it again, my drum tracks are out of alignment with each other, either causing phase issues or flamming, depending on what i set the hardware buffer size to, it will alter the alignment issue, but never solving the problem. I have delay compensation switched on to "long". Im not sure what needs to be done from here, and i struggled to find an Avid email for customer support without having to pay money. This band is planning to go to print next week, stress! If anyone could please offer any advice, i would really appreciate it.
Thanks!