I recently ran into a serious problem with quicktime and wanted to know if anyone else has had this happened.

My work flow is that after I've finalized editing a movie I export it as a quicktime, use compressor to convert it to mpeg2, create a dvd, and delete the captured and rendered files.

I had a client who needed to go back and make minor changes, but when I tried to open the quicktime movie it wouldn't allow me, saying it needed another file. Luckly the client still had the raw footage on tape. Under what circumstances does a quicktime export dependent on other files? I aslo noticed a self-contained option for export. Now I'm going to use that to avoid this from happening again.

Under what circumstances does a quicktime export dependent on other files?

When you export as a reference movie.

If you want to archive your final cuts, always choose "Make movie self contained".

Yup,

My production process is very much like yours - like he said, just make sure when you're exporting the quicktime movie (to use in iDVD or DVD Studio, etc.) you select "make movie self-contained".