KDE 4 slow with proprietary NVIDIA driver

Hi all,

Installed openSUSE 11.1 over the weekend with KDE 4. Unfortunately, as soon as I installed the latest NVIDIA proprietary drivers from the NVIDIA repository, responsiveness in KDE 4 dropped horribly, although compositing works. I’ve got a Quadro FX 1600M.

I remember reading about poor NVIDIA performance with early releases of KDE 4 but I thought those problems had been solved with the most recent drivers. Can anyone shed light?