Need help with QuickTime Codecs (Casio .avi file playing only audio via iPhoto)

I am trying to figure out how to get the videos I take with my digital camera (Casio EX-ZS10) to play via iPhoto. When I open them in iPhoto, they automatically play in QuickTime, which has audio but no video. I've already determined they play fine in VLC, but haven't figured out a way to force iPhoto to use VLC (even changing the file to play with VLC by default didn't help). So there are two acceptable solutions, neither of which I know how to do:

1--Change iPhoto to play videos in VLC
2--Add the right component/codec in QuickTime to play the files correctly.

The files are .avi files

Here is the VideoSpec analysis:
***** Analyzed File Results *****


*** General Parameters ***
- Name: CIMG0010.AVI
- Container: AVI - Audio Video Interleaved
- Size: 85.88 MB
- Duration: 28s 233ms
- Bitrate: 24.3 Mbps


*** Video Track Parameters ***
- Format: Motion JPEG
- Bitrate: Max.: Undefined / Average: 24.1 Mbps / Min.: Undefined
- Frame rate (fps): Max.: Undefined / Average: 30.000 / Min.: Undefined
- Encoding profile: Undefined
- Image size: 1280*720
- Pixel Aspect Ratio: Undefined
- Display Aspect Ratio: 16:9
- Interlacing: Progressive


*** First Audio Track Parameters ***
- Format: MS IMA ADPCM
- Bitrate: 176.4 Kbps
- Resolution: 4 bits
- Rate: 44.1 KHz
- Channel(s): mono
- Position: -


*** Miscellaneous ***
- Subtitle(s): No Subtitle
- Album: Undefined
- Performer: Undefined
- Genre: Undefined
- Encoded date: Undefined
- Album artist: Undefined

In the HD>Library>QuickTime folder are the following:
AC3MovieImport.component
AppleIntermediateCodec.component
AppleMPEG2Codec.component
ApplePixletVido.component
AppleProResDecoder.component
AppleVAH264HW.component
CASIO AVI Importer.component
DivX Decoder.component
DivX Encoder.component
EX_M4S2.component
Flip4Mac WMV Advanced.component
Flip4Mac WMV Export.component
Flip4Mac WMV Import.component
Perian.component
QuartzComposer.component
QuickTime3GPP.component
QuickTimeComponents.component
QuickTimeFireWireDV.component
QuickTimeH264.component
QuickTimeIIDCDigitizer.component
QuickTimeImporters.component
QuickTimeMPEG.component
QuickTimeMPEG4.component
QuickTimeStreaming.component
QuickTimeUSBVDCDigitizer.component
QuickTimeVR.component


These are all also in the
HD>System>Library>QuickTime folder and the
HD>Users>Me>Library>QuickTime folder.
I'm not sure WHICH Library/QuickTime folder they're supposed to be in.

I am running Mac OS X 10.5.8

It's been suggested that there's a conflict between codecs, so I removed them all and re-added them one at a time. After adding each one, I opened QuickTime, played the file, got only audio with no video, then closed QT, added the next one, etc.

 

Yes, if you'll notice in the list of codecs installed, Perian is one of them.

 

Resolved, for those that may search this in the future.
Left only Apple- and QuickTime- and Perian codecs in ALL THREE QuickTime folders. Then I moved all the files to another folder, deleted from the iPhoto library and re-imported to fix the thumbnails.