I was frustrated by the continuous disconnect issue, too, but finally figured it out. Here's what you have to do:

Go into Connection Manager.
- click on Tools - Connectivity Settings
- choose your network as default, and check the Use Without Asking box. Also set the WLAN idle time to Unlimited.

With these settings, you'll still get disconnected from time to time, but it should be transparent to you as the connection will be restablished in the background. Hope this helps.