Random Quicktime Error -50 on FCP 7 Export

I'm experiencing an issue where about half the sequences I send to Compressor 3.5.3 from Final Cut Pro 7, encounter quicktime error -50. There doesn't seem to be any common link between the sequences that encounter an error, and ones that don't. In order to work around the issue, I've had to re-encode the raw footage in the sequence to another format, then send to compressor again. However, this really slows down my workflow, because I'm normally sending about 10-12 sequences daily with about a 50% failure rate.