I've followed the instructions in that KB article; thanks.
Unfortunately it's made no difference. I know my clients *can* get updates from the server - one box that was running with Dec-09 IPS has now updated to the Dec-30 IPS - they just don't seem to be getting an actual up-to-date version.
LiveUpdate has run successfully, I can paste the status report in if people think it would help - everything returned successfully though, including "Intrusion Prevention signatures Win32 11.0 was successfully updated."
If I look at LiveUpdate Downloads under LocalSite tasks it doesn't show anything particularly up to date - even showing the AV signatures as 2009-12-31 rev 117, even though I'm actually on 2010-02-09 r52 across the site (i.e. up to date). Whether this is just a display issue or something larger, I don't know.
WSUS is also installed on this server although both seem to be playing nicely at the moment, but it's always a possible cause of errors.
Where can I see the list of IPS to check how many I have downloaded (i.e. if I have the full 1821)?