ablazhov,
Frankly speaking, for web protocols like Skype there is no such a thing like disconnection... these protocols are stateless, i.e. they can start & continue execution from any point, running no persistent connections.
The protocol implementation in Miranda presumes the existence of that persistent connection, to simplify packet handling, but in this case you can be dropped from a frontend server time to time, that's a normal practice to better spread the workload among the servers.