This won't help, but you arn't alone. We have Sketchup7 installed on about 80 PC's in some of our computer labs and they all crash if you try and access the 3D Warehouse.
Other PC's in differnt labs are fine, other people connected to the same netwokr through a laptop are fine. We're stuck as to the reason why - we can only assume it's a hardware or a network conflict somewhere.
We can only get Sketchup to work if we deactivate 'use hardware acceleration' in the OpenGL Toolbox, but this has had no effect on the 3D Warehouse.