No external display through thunderbolt on 10.6.8

Question

Ok so I have a 2011 MacBook Pro (8,2) and I use a mini displayport to HDMI adapter to connect to my tv or external monitor. It used to work fine (a few months ago) but now it doesn't do anything when I plug it in, but when I pull it out the screen flashes blue for a second. This is all under 10.6.8. I triple boot this machine and under 10.7 and Windows 7 the external display works fine. It also works fine with a 2009 MBP 5,5 that is running 10.6.8. The only difference I see is that the 09 MBP is actually mini displayport whereas the newer has thunderbolt and under 10.7 there was an EFI update and I think a thunderbolt update that wasn't offered under 10.6. My question is can I somehow get the external working under 10.6 with a software tweak/fix?

Answer 1

Thanks - this thread does address the MPEG problem but I still have no sound whatsoever on any program or the system. If I try to preview a music file in the finder with no other program open there is no sound as it won't play. iTunes just crashes when opening with this error:
Process:         iTunes [467]
Path:            /Applications/iTunes.app/Contents/MacOS/iTunes
Identifier:      com.apple.iTunes
Version:         11.0.2 (11.0.2)
Build Info:      iTunes-1102025001000000~1
Code Type:       X86 (Native)
Parent Process:  launchd [104]
Date/Time:       2013-05-09 13:39:50.421 +0100
OS Version:      Mac OS X 10.6.8 (10K549)
Report Version:  6
Interval Since Last Report:          1616875 sec
Crashes Since Last Report:           4
Per-App Interval Since Last Report:  3334226 sec
Per-App Crashes Since Last Report:   3
Anonymous UUID:                      141AE784-E67D-40A9-A793-F9DFEED553BA
Exception Type:  EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000000000000
Crashed Thread:  0  Dispatch queue: com.apple.main-thread
- that's why I think it's a system problem.