Rightclick Scrollmode

I just tried the Alpha and something I found really weird was, that when you rightclick with your mouse to deselect, you also enter scrollmode...that is really annoying! How can I disable that? Is it just a bug or a problem on my side with my mouse/computer?

Edit:
Okay after restarting two times it seems to work. I think it has something to do with using alt+tab to get on the desktop.