I have found a problem related to a particular application that is running on the server. It was using a lot of CPU time and I think this was related to the lag reports coming from different people. I reckon this has been present for around 2 weeks, maybe longer.
On a related matter, the server will be rebooted in about 20 minutes from the time of this post. I expect it will be down for maybe 20-30 minutes.
Proud member of "the most paranoid group of people in the community"