No Launch and Distortion

[Cutlerbri]

Just when things were going so well....
I upgraded to PT 10.3.7 and PT 11.02 today. From what I understand they can co-exist on Mountain Lion, which I have. They worked for a little while but now PT 10.3.7 "quits unexpectedly" on launch (it hangs up just as it's installing the AIR plug-ins). I can still open PT 11.02 but it's now horribly distorted when I try to play back.
I have optimized the iMac, uninstalled and re-installed software for PT 10.3.7 and PT 11.02 twice. Re-loaded the Mbox 2 driver twice. Restarted, restarted, and restarted.
What can of bees did I just open here?

Pro Tools Configuration:
iMac 2.8 GHz Intel Core 2 Duo
4 GB of memory 800 MHz DDR2 SDRAM
OSX 10.8.4 (Mountain Lion)
Pro Tools 11.02., Pro Tools 10.3.7
Mbox 2 (blue with handle)
OWC Mercury Elite Al-Pro 500 Gb Firewire harddrive (2)
Oxygen 61 USB keyboard

[Cutlerbri]

Update. Able to open a functioning PT 11.02 now without distortion but PT 10.3.7 still crashing before it opens.

[Cutlerbri]

Another update: I made a clean uninstall of PT 10.3.7 and reinstalled it, reinstalled the Mbox 2 driver, re-optimized the iMac (deleted prefs, etc.), restarted, and now both PT 10.3.7 and PT 11.02 seem stable.

I'm not sure what my earlier problem was but apparently one more Roto-Rooter job was needed. Wish me luck, guys.

Brian