Evenin' folks.
As above, I banned/deleted the guy and his posts earlier; but although the posts are gone, any references to any of them in forum indexes as 'last posts' will still be shown - there are two ways for me to get around this... 1) rebuild a load of counters and caches; this will certainly fix the problem, but although it shouldn't be, experience tells me it's fairly server-intensive and may require taking the site down for a few minutes to get it done smoothly. Or, 2) as it doesn't really pose any massive problem, just wait until there are new replies and/or the affected posts are bumped down; and then those invalid 'last post' links will just disappear.
I'm thinking of running with option 2 - we're not even 12 hours on from the posts appearing, and most of the now-dead links have been bumped into oblivion, it's only a matter of time until the rest go the same way.
All the best,
Rob.