Some of you might have experienced issues with mining during the last weekend, particularly if you were connecting to EU servers. This was because one of our EU backend servers started to fail on hardware level. However, as it was still partially accepting connections, which would eventually fail, the machine was regarded as "running," and therefore our load balancer didn't detect this issue properly. Only if your connection request hit this particular failing server, you would have experienced occasional drops in EU connectivity.
The machine has been now been replaced by a new one.
We apologize for the issues and thank you for all the reports!