so u were able to connected for some among of time and got disconnected.
This can be a result of mutiple things, I had something simliar happened with sql server, and turned out its my was client's stupid network security.
To isolate the problem, lets start with your application first, have you tried this ?
if driver is not a problem, your next step is most likely to trouble shoot the network's security setting, maybe there were changes happened recently.
hope that helps