Thanks for the update. I've been on MD's since November last year and these last few days are the first time anything much has gone wrong. Is it just coincidence, or have your web hosting people made some recent changes? Or could it be a result of malicious attacks, as there has also been this recent flurry of abuse of MD's.
Because I work in computing, invariably I see things going wrong mostly when changes are made. Not that change is bad, but often not all the implications are considered properly and not enough relevant testing is carried out.
The problem was with the IIS, the version it was running had become unstable for some reason and in periods of heavy traffic, it was failing.
Initially the server was rebooted and then once again it wobbled (technical term ), it has now been reinstalled so all being well we should have stability once more.