ITunes 10 Plays No Content Locally After Emergency Disk Migration

Question

All:
I have an MBP (Late-2008) running OSX 10.6.6 with iTunes 10.1.1(4). Recently, a low disk space condition on my external FireWire drive holding my iTunes library clued me in to an impending disk failure of that drive. I purchased a new drive, and used CCC (Carbon Copy Cloner) to clone the disk while still operable, which was successful, to a drive of the *same exact* name.
iTunes now finds all my content, which syncs & plays on my new iPad and older iTouch flawlessly, however it refuses to play any content locally, whether purchased from the iTunes Store, old CD's I imported a long time ago, podcasts, movies, or imported video MP4 content. Clicking Play shows nothing / no error messages, and double-clicking the files directly on the new disk results in being redirected to iTunes, but no content plays.
So far, I've tried de-authorizing / re-authorizing my MBP, but that doesn't explain why imported content doesn't play.
Following the instructions to re-build my iTunes Library results in a not useful library that had no content.

Answer 1

Odd ... that BEX error citing the QuickTimePlayer.dll (like the DEP errors and the unknown module for the iTunes errors) also suggests old, misplaced QuickTime componentry. But the lack of any QuickTime Player launch errors, or at least relentless "software out of date" messages, speaks against that possibility.
... I think we'd better check for old, misplaced QuickTime componentry anyway, just in case. (The symptom-set for that sort of trouble is in a constant state of flux anyway, so the lack of launch errors probably can't be taken as conclusively speaking against it.)
First we'll need to adjust some view settings on the PC.
1. From the Start menu, click Open.
2. In the Organize menu, click Folder and Search Options.
3. Click the View tab.
4. In the "Advanced settings" pane under "Hidden files and folders" make sure that the "Show hidden files and folders" option is selected, and the "Hide extensions for known file types" option is unchecked.
5. Click OK.
Now we'll go looking for old QuickTime stuff in the most likely locations for it to show up.
In Computer, open your C drive (or whichever drive your operating system is installed on).
Open the "Windows" folder.
*If you have a 32-bit version of Windows,* open the "System32" folder.
*If you have a 64-bit version of Windows,* open the "SysWOW64" folder.
What files or folders with QuickTime in the file or folder name can you see in there? (In a standard installation of QuickTime, you should see precisely two files ... QuickTime.qts and QuickTimeVR.qtx ... and no QuickTime folders whatsoever.