In my map, there are some odd occurrances. First, I have the diable vision trigger (under "start"), but most of the time, later, you can see your own units again. Perhaps I overlook something, but I can't figure out why it happens. Also, about one in every 3 times I play the map, SC freezes in the middle and I have to manually exit it. Any idea?
I'm not sure about your first problem, but you may have to uncheck the randomize start locations for both Force 3 and 4 too. This is just a guess.
Your second problem is most likely a sprite problem. Freezing is usually caused by an endless loop on a sprite.