M-g works, g doesn't

[Richard E Maine]

I've got a workaround (several, actually), but I'm puzzled about what
is happening.  Maybe if I understood it better I could keep it from
happening instead of doing workarounds...

Recently switched the nntp server that I use from work.  (Dryden
stopped running their own, so I'm using an external commercial
one - supernews).  Still experimenting with the best way to do things.

I am going through a firewall/nat, which may well be related.

When I leave gnus alone for more than a few minutes, the "g" key
(gnus-group-get-new-news) stops doing anything useful.  No errors,
it just never sees any new news.  Yes, I've checked the server
buffer and the server shows as "open".

Now if I do almost anything *except* g, things start working.
For example, if I enter (with =) and then exit any group, then
g will work.  If I quite and restart gnus, things work.  The
simplest workaround I've found is to do M-g (gnews-group-get-new-
news-this group), after which g works (on all groups).  I find
it odd that asking for a particular group kick-starts it, while
asking for all groups doesn't.  Alas, the one thing that doesn't
work (g) is the one that my fingers are most trained to do when
checking for new news.

My best guess, based on symptoms instead of looking at the code,
is that somehow my connection has been closed or otherwise made
unusable, either by the server or our firewall/nat, even though
gnus doesn't "notice".  Apparently M-g automatically re-opens
the connection when it isn't working, but plain old g doesn't.
Why the difference I don't know.

I can deal with the workaround once I get used to it (which I
haven't yet).  But it puzzles me.  Insight appreciated.

-- 
Richard Maine                       |  Good judgment comes from experience;
email: my first.last at org.domain  |  experience comes from bad judgment.
org: nasa, domain: gov              |        -- Mark Twain