If I click on a TextMate window to select it and the tries to adjust a split view divider (file browser or output view) the window moves instead of adjusting the divider. I doesn't always happen but sometimes it does.
I'm using TextMate beta5 on OS X 10.9.5. I made a screen recoding of the behavior:
[1] https://drive.google.com/open?id=0B7UtafxGD9vEU2RPZHhXYlRCenM&authuser=0