Only CERTAIN videos will not import in BOTH versions of iMovie

Question

Heya, I'm dying here, hoping someone can help:
I've been filming video with my camera, but for some reason, one out of every 6 or 7 times a file will absolutely not import into iMovie.
They play absolutely fine with audio and everything in Quicktime, but when I try to import to iMovie '08, they simply do not show up as thumbnails even though it goes through the whole "creating thumbnails" process.
When I try importing them into iMovie HD 6, I get a "file cannot be imported: unknown error" message.
Everything else I film with my camera and import into either version of iMovie works just fine! It's only certain ones... but it always happens to be the most important clips!
There's GOT to be some way to fix this, right?

Answer 1

Everything was filmed with the exact same settings.
Your argument here is "inductive" and does not confirm that all stored files are in fact in the same compression format and settings. You need to apply a "deductive" approach. As I implied and QT Kirk specifically stated, you need to actually examine the files to determine their internal specifications -- comparing the working with non-working files to look for differences.
I've tried Streamclip, but when I try to save it as an avi, mpeg, dv, or even a renamed mov file, it says "Error: Could not prepare clip"
If your are trying to use the "Save As..." option here, you are not, in fact, performing a "conversion" but rather merely attempting to place the same content in a different file container. MPEG Streamclip does not, for instance, have the ability to export non-MPEG2 content to MPEG (MPEG-2 'muxed" or elementary streams) which would be incompatible with iMovie '08 in any event. As to AVI, you mush have one of the required AVI QT components installed and the compression formats you are trying to place in the AVI container must be compatible with the AVI container which is itself compatible with iMovie '08 as long as its contents are already edit compatible. As to DV, this one one usually difficult to mess up unless you were trying to turn it into a transport stream.
today I tried taking the original quicktime MOV file from the camera (the one that plays just fine in quicktime AND streamclip, just won't convert or import)
This statement seems to imply that something is wrong with your attempted work flow. If the file opens and plays in the QT Player and MPEG Streamclip, then it should be convertible. Once again, the primary problem is determining how to best perform this conversion which is why Karsten, QT Kirk, and I need specific information regarding the actual compression format, whether or not the compression settings were compatible with the QT structure, and whether or not an extraneous track (e.g., a "Tweener") might be causing difficulties. Posting a screen capture of the "Inspector" and/or "Properties" window or a sample file should provide the needed information.