We've had some serious technical issues, and are still investigating the cause. We tried basically everything we could to fix the servers, of course. No luck though, We made some changes that might or might not have fixed the issue but we can't know for sure ATM. I am personally not convinced that our actions helped, more like the server finished some background process that was bogging everything down and making the site unusable.
Hopefully it won't happen again, which would mean that we managed to stumble upon a solution, but it more likely to happen again. All we can do now is to study the logs and try and find a cause...