Follow-up : I checked the "Disable registration" box in the Network tab on debug configurations for the simulator. That seems to have shortened the MDS timeout-hang to about 30 seconds. MDS must be having problems (?on my machine?) registering the network? Since I don't know what it was trying to do I can't really say what a solution might be, but disabling it helps.
All networking works fine after that.
Last edited by kenjkelly : 05-22-2009 at 04:14 PM.