I've been looking into it on the SMF support forum, and it appears that we'll
have to dive into the forum code and, in IT weasel speak, 'chmod line XXX on
template blah-blah to change value M to =yada yada'
I'm not awake enough at the moment to face that dragon, however, it appears that
a 'temporary' user work around is to regularly clear cache and to load the forum cookie
anew at each session. Evidently an individual user's browser settings can also affect
the session time routine, of course after making that statement none of them
mention what those settings may be.
Sorry for the inconvenience folks and I'll attempt to address the issue ASAP.