Will update my testing install and check again.
Strange enough i didn't get engage to work without the 1/3 black screen on my testing install untill i copied my custom compositing profile from my stable install. Must be a setting somewhere apparently cause now engage works perfectly on both installs with proprietary ati driver.
Only problem i still have is bad looking gtk apps (fonts in particular) with composite module enabled. Oddly enough the problem doesn't show when i make a screenshot of the window.