Mousemovement speed affects my windows mouse movement speed

I play League of Legends at home and at work(yes I am one of those lucky guys).

At home I have a high DPI mouse with a state of the art mousepad etc. At work I have the god of all mice MX310, however it's an old low DPI mouse. The problem is that I have to set my mouse speed in League everytime I switch locations, because the settings are now saved online(is there a way to turn this off?).

The real problem is that whenever I open my first League game at the other location it somehow sets my windows mouse speed up or down depending on if I go to work or come home. Really really strange bug. At first I thought I was just not used to my new mouse yet, but I have had this issue several times and I have tested it as well.

So basicly at work my mouse speed in League is 65 and at home it is 30. So when I go home, my windows mouse speed somehow speeds up and at work the mouse cursor goes to crawling baby speed.