I am getting mysterious .event files - always empty, created by me a few weeks ago - in several local project directories. They are all Subversion checkouts. They are always named after the directory they reside in, so a directory named pagination will contain a pagination.event file.

Does anybody know what this is?

Possibly important information:

• I am working on a Windows 7 Workstation
• I use NuSphere's PHP IDE (no updates recently)
• I use TortoiseSVN for version control
• I set up a Windows 7 backup job recently that ran once, I can' remember when exactly.
• The event files seem to turn up only in repositories
• There is no external access to those repositories