Pinguy 14.04.1: AMD Open Source Driver - got someone hibernation working properly?

Hi y'all,

I own a ATI 7850 graphic card and I run Pinguy 14.01.1 64bit on an AMD powered system.

Hibernation is for a me a must have - but I have trouble to get it to work.
It seems that it only works with AMD catalyst drivers - but which I had to purge lately due to other issues.
I went back to the open source driver - hibernation does not work at all...so far.

Did anyone got to work w/ open source drivers in place w/ AMD graphic board?

What is the latest open source driver and how to get it?
Does anybody use this feature at all?
Any advice?

Thanks,
LNT