[imp] Unexplained session problems

[Kevin Konowalec]

Our users have been complaining that they are getting booted out of  
their sessions without explanation.  They are well within the timeout  
values set in php.ini.  I've tried it myself and sure enough even  
just leaving imp open to the inbox, refreshing automatically every  
few minutes, I get kicked off with a "Login Failed" message fairly  
quickly.  Other users have reported getting booted to the login  
screen on submitting an email as if the session had timed out but  
they hadn't been logged in long enough to have had garbage collection

I get the following error:

Feb 07 14:01:30 HORDE [error] [imp] FAILED LOGIN xxx.xxx.xxx.xxx to  
xxx.xxx.xxx.xxx:143[imap] as someuser [on line 247 of "/var/www/horde/ 
imp/lib/Auth/imp.php"]

Has anyone else experienced this?