Hi I was having troubles with my mouse when I was playing games on steam on cedega (for example counter-strike)
the mouse didn't want to dissapear from my screen (so I had a mouse in my crosshair), In the menus the mouse didn't work either like it should. (It pointed to high)
here's the work around -->
In the profile configuration, use the option to play in a window. and hide your taskbar so it does not get in the way. Then the mouse works properly.
I hope this helps some other guys.
Maybe you have a better work around --> post it here plz