Well I must be missing something obvious, but I noticed last week I didn't have any commercial skip XML files for any of the shows in my B:\Movies directory. I figured I must have cleaned up the C:\Users\Public\DVRMSToolbox\CommericalsXML folder some day and deleted them by mistake. Next day, the movies I re-scanned no longer had XML files. Rinse and repeat. (But backup the dir.)
So the DTBFWService_xxxx.log file shows the XML files being deleted every day at 5:04pm. None for the shows in my D:\Recorded TV (unless the WTV is gone), but all of those for all of the .WTV files in B:\Movies. I've unchecked a lot of options and made sure B:\Movies is one of the watched folders.
Watched folders are:
Attached are reg settings and a screen shot of the file watcher tag.