Is very important to fix this kind of bugs because that was an Arena that I have paid with real money and I was 4-1. I don't mind disconnect in constructed mode, but a solution must be found when you are gambling real money.
PS: I understand that now we are in beta times, but I think this is a big issue that must be fixed before release. No one will play MGTO if you suffer several disconections while playing. (MTGO has the possibility to login again, even if you lose one or two turns)