> I think it's the inverse of that problem: my simple shell sessions
> stay alive for weeks and weeks, as I'd expect. I can unplug my entire
> router/cablemodem structure, and fart around with recabling for a few
> minutes, and (so long as I wait a minute or so after re-plugging) I
> get normal response time.
> It's the Emacsen which die overnight.
This might sound silly, but way back in the dark ages of university
computing, the sysadmins would run reaper jobs that would hunt for idle
processes using lots of CPU time or memory (*cough* Emacs *cough*) and
kill them off. Are you sure it's not something simple going on?