from what point on do you not see your mouse? do you see it before log in?
can you post your mouse brand and model maybe? and basic systemspecs to get them click start and type dxdiag in search, a program starts with a green bar filling. when that bar is filled hit save information and save it to where you can find it.
I am not really sure if i can help here so , certainly if you have this problem only after login and entering the game, you should submit an official bug report with the info i asked above submitted in the bug report also. you can do this here http://www.aeriagames.com/contact/support
also there i can not guarantee a solution but of course they can look at other places then we do