After having more problems installing the proprietary driver for my HD4710 ATI graphics card, a forum post pointed me towards a tool named SMXI. This will automate the dist-upgrade of your system, but more importantly, is a simple way to install the current fgrlx drivers without any weird performance issues!
Also note that for crunchbang linux I had to use “radeon.powersave=0″ as a boot parameter rather than the normal nomodeset.