Tags deleted with manual category organization

Has anyone every seen this ...

In my PSE Organizer 5 preferences, under Tags&Collections I have everything
EXCEPT Category set to alphabetical. In the last few days I've added a few new
tags and done some shifting, so my categories got a bit scattered. I decided to
move them (the top level categories) around (using the drag and drop method). A
few times when I moved a category all of a sudden a few of the other categories
would disappear ... a bit of research showed me that they were actually deleted
(from the photos as well as the tag bin). This led me down a three hour
investigative path of various testing to discover:

If I try to order tag categories around manually then something goes south in
the database, as even if I successfully finish the manual organization, if I
then run File-->Catalog-->Recover it comes back with a bunch of tags
deleted. If I leave all the tags alone (no moving or sorting) and then run
File-->Catalog-->Recover everything is fine. Also I can change my
preferences to Category=Alphabetical and the organizer will appropriately shift
the categories, and the catalog recover function will finish successfully. So
the tags are being deleted ONLY when I manually organize/move the categories.

Any ideas? It's not a HUGE issue as I can live with the categories being
alphabetical, but it is a bit annoying and now I'm worried there is something
wrong with my database that will pop up later on (even though I have
successfully reconnected to all missing files and run a catalog recover).

Sorry for the delay, I've been away ...