It would seem that someone has been having a go with D.O.S attacks (|Denial of service) on the site, this lead to the slow down.
All I can think of is that some person/s have an issue that they're not happy to sit and chat about but would rather try the underhand route
We're sorting it out and we've informed the authorities so all should be well.
On a seperate note, the upgrade to the forum that has been talked about for a while will take place in the near future which will lead to some down time so don't panic!