Rendered Final Cut files not showing up/disappearing in finder

[dbbubba]

I am having a problem where once I render audio files only four or five files will show up at a time on my drive when looking in the finder.
If I try to import the rendered files in iTune only a few will show up at a time.

I am rendering a bunch of audio files in Final Cut Studio and I have rendered hundreds in the last few weeks.
Now only four or five will show up.
The new ones rendered make the old files disappear in the finder.

I am running OSX 10.4.11
My external drive is a Maxtor One Touch III 750 GB

This system has worked fine for two weeks, but this week something changed.
I am not doing anything different.

Any ideas?