agent % mark get over ridden somehow

agent % mark get over ridden somehow

[Harry Putnam]

This is an irritant I've run into often enough to cause this post.
It's not totally reproducable, at least I don't know how to reproduce
it on demand.  However it continues to happen so apparently some set
of circumstance will provoke it.

Seems like it might be a case of gnus listening to the wrong
information source.

Circumstances I do know about:

While unplugged:
Mark a message that was not retrieved by download score rules with %.
In semi-recent and up Oort one can then (theoreticlally) while in the
same summary buffer, press `J j' to go plugged then `J u' to download
current group, and snag any messages with % marks.  Then return to
unplugged with `J j'.  

If I then try to access that message later when unplugged I get the 
`G' symbol and am told it has either been expunged or is not
available.  But wait, I just down loaded it a few moments ago.

Somehow gnus doesn't believe that.  But a search of the directory
shows the message is in fact there.  None the less, gnus obstinately
tells me it isn't.  Even if I press `j' and feed it the article number
or message id.  Seems like some record gnus is looking at is giving it
bad information.