IMovie suddenly quits...project disappears...was almost finished..???

Question

I teach in a small northern Wisconsin school/community, the art teacher...and we are moving into videography. Bought a Canon XL2 camera...have a Mac lab...one iMac and eMacs. Our computers are on a network.
I'm trying to work thru the learning curve myself so I can teach this to students. Twice now nearing the end of the developing video process, the movie suddenly quits. Trying to open the "Recent" by clicking on the upper left blue Apple suggests the file was never there, never existed.
The second time this happened was tonight. I had an hour length video with 20 hours of after school time into it. I had already burned the video once minus audio so we could write a script and go into our recording studio to lay tracks. Was near finished when it suddenly disappears, so it feels a bit like a kick in the gut to see this happen. Most assuredly the students will not have the resilience even once to rebuild a movie that suddenly disappears.
Our tech guy isn't quite sure what's happening either.
One thing we do see is that our Gig space consumed in the making of the video is not being returned after its disappearing...so it is chewing up memory apparently existing somewhere.
I'll have to rebuild this video beginning shortly, but wondering at this point what is to prevent this from happening all of a sudden once more???
We have iMovie 5/ iDVD 5
thanks for your thoughts on this...
Larry
outdoorpainter
iMacs and eMacs   Mac OS X (10.4.3)  

Answer 1

Here's a thought. The error message about conversion may be misinformed. Think like a programmer for a minute. The routine he writes opens the iMovie project file that's inside the project package. He has iMovie read the file looking for a flag that tells iMovie which version made the project. The flag that iMovie expects doesn't say iMovie 5, so iMovie reports a version error to you and offers to convert the project.
But the file is fine. The problem is with the data iMovie evaluates, not the file. iMovie couldn't read it correctly because of some unexpected factor. Perhaps the server uses a disk format iMovie doesn't understand. Then iMovie's analysis would lead to the wrong result because the data isn't delivered in the format iMovie expects. Where a version flag should be, the project file says "horse feathers". Obviously that's not iMovie 5, so iMovie offers to convert it.
If something like that is happening, the problem may be caused by storing the project on the district server. Try storing the project locally.
I have no experience working with iMovie in an environment like yours, so I'm just guessing. I suspect, however, there may be lots of different disk/networking factors that might cause a failure like you see.
We do know this: iMovie expects us to use the Mac OS Extended disk format. When a local disk is something else, we get unexpected results.
Karl