Anytime I play (whether through the editor or straight from one of the demos included in the UDK pack the view constantly pans upwards until I am looking directly up at ninety degrees. I can still look up and down with the mouse but it does not stop the constant panning upwards. On exiting play in editor my cursor remains stuck at the top of the window until I alt tab, similar to the issue mentioned here.
This happens when running both the 2012-05 and 2012-02 version of the UDK. I am running on Windows 7 64bit. I've tried multiple mice with all resulting in the same issue.