In my previous game my ally (Protoss) was dropped from the game. I went to control his units but I had a large problem - I was unable to build any buildings within his pylons. Furthermore, when I built my own pylons with his probe (I was Zerg), I was still unable to build any buildings. Also, my ally had research warp gate but I did not get the little warp gate symbol that appears on the bottom left side of your screen.

Thank you for letting us know about the issue, but for the future please use the Bug Report forum on the official StarCraft II Beta forums: http://forums.battle.net/board.html?forumId=25498616&sid=5000

Thanks!