Sounds like there is something else in start up that is taking the focus away from the mGalaxy screen until you click the mouse to regain focus. Is there another window open behind mGalaxy that you can see ?? Like file explorere, a video window, internet page. I know when I boot my computer in the mornings, I have a little pop up window down in the corner thats tell me Anti-spyware missed a scheduled scan and wants to do one (because the PC was off at the scheduled time). Anything like that can take the focus away from mGalaxy...
I suggest clicking the mouse and when you can start selecting things in mGalaxy, shut down the program and see if theres any windows open....