Problems with Applications

Hi,
When I try to open most Applications (incl. iPhoto, iMovie, iTunes, etc...) on my Mac Mini I get the following message:

"iPhoto [for example] cannot be opened because of a problem"
Under "Problem Details and System Configuartion", I get the following message with respect to, say, iPhoto:

"Process: iPhoto [567]
Path: /Applications/iPhoto.app/Contents/MacOS/iPhoto
Identifier: com.apple.iPhoto
Version: 8.1.2 (8.1.2)
Build Info: iPhotoProject-4240000~8
Code Type: X86 (Native)
Parent Process: launchd [105]

Date/Time: 2012-11-19 21:20:13.701 -0800
OS Version: Mac OS X 10.6.8 (10K549)
Report Version: 6

Interval Since Last Report: 525505 sec
Crashes Since Last Report: 102
Per-App Crashes Since Last Report: 5
Anonymous UUID: 05EEFA95-EF07-47D0-BAFE-883E8878F8FD

Exception Type: EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000002, 0x0000000000000000
Crashed Thread: 0

Dyld Error Message:
Symbol not found: _QTAddImageCodecType
Referenced from: /System/Library/PrivateFrameworks/MeshKit.framework/Versions/A/MeshKit
Expected in: /System/Library/Frameworks/QTKit.framework/Versions/A/QTKit
in /System/Library/PrivateFrameworks/MeshKit.framework/Versions/A/MeshKit"

Under that is LONG description of the "Binary Image".

What the #@%@ is going on? What can I do to solve this?

Boot the Mac Mini with your Snow Leopard DVD and run Disk Utility from the top menu Utilities. Once in Disk Utility, press the "repair permissions" button. After it finishes, boot back into Snow Leopard normally and try to run the application again.

I have tried running the "Reapir Permissions" function from Disc Utility, but not after booting from the original DVD. Iwill try that and we'll see...

I have tried to insert the "Mac OS X Install DVD" into the disc drive of my Mac Mini, but it will not accept it!? In fact... it will not accept any disc at all... almost as if there is already a disc in there that refuses to eject!? So... now what?

If there's a disk in the drive of your Mini, reboot the Mini and hold down your mouse button at the same time. The disk will eject.

The problem is that I really don't know if there's a disk in there or not!? I'm not the one that uses this computer the most. My son told me about the problem in the first place, and also said that one of his friends brought over a game disk not long ago. But he can't remember if they inserted it or not. Anyway I have tried booting with the mouse button pressed... nothing happens! Does it make any difference that I have a wireless Apple mouse and a wireless Apple Keyboard?

A few more observations... when I go into Disk Utility and look under the Optical Drive (HL-DT-ST DVDRW GA32N) it says the drive is EMPTY! If so... what else could cause the optical drive to refuse accepting a disk? Has it failed and need repair? One last thing, my son told me that he and his friends have been playing a game called MINECRAFT a lot on this computer and that every time they do so, the computer gets REALLY HOT... almost too hot to touch!!! Could this be part of the problem?

It does sound like the optical drive may be defective or dirty. As far as the computer getting hot when playing a game for long lengths of time, that's not unusual. If the machine overheats, it will shut down. It's protected by thermal sensors.

Back to the optical drive... Buy a can of compressed air at Radio Shack or any other store that sells electronic accessories, and use it to blow a couple of short blasts of air into the optical drive. That should clean it if it's dirty and not accepting disks.