Hi ,
I keep running into related bugs and it all seems to come back to second monitor. Whichever Unreal window is open in second monitor will usually only accept input from a stylus, and not mouse/trackpad that remain working on other monitor. I am using a Yiynova monitor (similar to a Cintiq) but I doubt it is an issue with monitor drivers since I have never had this behavior in another application. I assume you guys are testing with Cintiqs, have you had any similar issues with those?