Mouse will disappear sometimes. Only after login screen.
The visual will disappear. But it will still work.
Win 7 x64
Razer Deathadder/Hydra
If yours is wireless then this could be a problem with game as when I am in game a number of times resent my mouse has locked up and gone bonkers. Not sure if bug or glitch or hardware related but only seems to do after long amounts of playing on game with my sidewinder x8 And I can get around 40+ hours of hardcore gaming out of it befor needing to charge so i think might not be hardware but software error somewhere. Cant be 100% sure…
Will continue testing and reporting on this one 
Thx for posting Pwnaglnc you reminded me to submit my bug
Actually I own a hard wired USB razer deathadder. Not wireless so there is something there. Thanks for your input as well