I had a similar problem like many others for connecting to FSX with PlanG on a laptop over the network. I've setup PlanG exactly as explained in the manual but still every time PlanG was disconnected after about 20seconds because of timeout.

I've tried many of the solutions given in this forum, but what really did the trick for me was a small free utility called the "SimConnect config tool" (http://simconnectconfigtool.codeplex.com/).

Just wanting to help others with the same problem, I decided to share my knowledge...

Beautifull program by the way, thumbs up!