similar situation here. I even reinstalled Kubuntu from scratch. It worked fine, but as soon as KDE 4.5 is loaded - compositing is gone.
I tried enabling Xrender which works but is extremely slow. After enabling Xrender I cannot switch back to the OpenGL, so I have no compositing at all.
I tried compositing with radeon drivers and with oficial ATI drivers, but nothing worked.
I have ATI HD Radeon 4670 on Dell Studio XPS 1645 with i7 CPU, running Kubuntu 10.04 x64
similar situation here. I even reinstalled Kubuntu from scratch. It worked fine, but as soon as KDE 4.5 is loaded - compositing is gone.
I tried enabling Xrender which works but is extremely slow. After enabling Xrender I cannot switch back to the OpenGL, so I have no compositing at all.
I tried compositing with radeon drivers and with oficial ATI drivers, but nothing worked.
I have ATI HD Radeon 4670 on Dell Studio XPS 1645 with i7 CPU, running Kubuntu 10.04 x64