OK I've found out that this problem was due to a glitch in CPANEL - the software managing this (and other peoples) servers.
It briefly threw server time 13 hours ahead before it corrected itself.
Some people might find they cannot post and a message of :
"You cannot make another post so soon after your last; please try again in a short while."
If you get this message - your account is locked out until the time shown on the Who's online section (bottom of main forum. click Who's online) - at most now another 6-12 hours max.
This is also why the board is reporting so many people online - as their last online dates are ahead of us.
Because the glitch is fixed, all those future posts and logins will eventually expire and the board will return to normal.
POSTS
Some posts made during the glitch will have future times on them and as threads are date-sorted, they'll appear below any post you make until their posting date goes into the past, so please watch for this
Some people have closed their forums because of this, but I'll keep it open as to most, everything seems ok.
KGAdmin