13.04 dash problem

[BJLmsc7]

I dont know if this thread goes here but i just wanted to report a problem with the unity launcher, the problem consist that when i configure it to make it auto-hide the launcher hides but a purple stink stays in the place where the launcher was. i manage to solve it changing the actual driver in use that was the one from X. org X server (open source) and choosing the propietary fglrx( not the update), i am reporting this because i have read that is better to use the open source driver because the community can make changes to it and make it better so i am looking forward for a fix to this problem . thanks

My computer specs are the following:
Intel core i5 4570
Sapphire hd 7850- 1gb
msi z87-g43

EDIT: i also wanted to report that with the propietary drivers i notice the system faster opening every aplication.