Hi Denis, Konstantin, Larry,

Thank you very much for the feedback on this! I'm still unable to get
a situation where 'startup.mar' gets clobbered. But (now that I'm looking
closely) I do see that when I shut the computer down on my XP machine with
Guide still running, Guide clearly gets interrupted part way through the
"shutdown" process. In my case, it never gets around to writing out an
updated startup.mar, nor does it clear out the "cache" folder that is
right under the Guide one.

My guess would be that, given a little more time, Guide would have
gotten around to opening the 'startup.mar' file for writing out the new
version. That would make it a zero-byte file. Guide is clearly getting
the message from Windows that Guide should close up shop; but Windows
then pulls the rug out from under Guide, turning off power while Guide
is in mid-shutdown. A rather horrifying way to behave, in my opinion!

A bit of Googling shows some other programmers running into situations
where closing down Windows doesn't shut their programs down cleanly first,
and I've found some possible fixes. Now to try them out...

-- Bill