PT LE 7 - can't delete files from disk

[BradG]

This is a new problem which has just recently started happening to me.

After consolidating part of a region into a new one (like grabbing a loop out of a longer take), when I try to delete the older, longer file from disk, I get this error message:

""Audio_File.aif" can not be deleted from disk! Regions from it remain in this session. Do you want to remove it from this session?"

In fact, no regions of it appear anywhere on any tracks, or any of their playlists. In a few sessions, where I manually deleted the unwanted files (because they were 44 minutes long), the session wanted me to find them once it was re-launched.

Any idea what the problem is, or a fix?

Mac G5 2.5DP, OS 10.4.4; Pro Tools LE 7.1