Whenever I start a game, fog of war covers the entire map and I don't have any units or buildings. It also freezes everyone else who's in the game, but they can see their units and buildings. I don't know what the problem is, I have the latest patch and am running Windows 7 32-bit. I've been playing for a while but it all of a sudden happened after patch 9 or something, and I haven't been able to play since.
I had the same issue before. I reinstalled (uninstall then install again) and it fixed it completely. I'd recommend you do the same.