Apparently the Kwin developer does not do extensive hardware checking, and the driver he was using for his R700 ATI card on his distribution didn't work, so he has disabled Kwin compositing for everyone using the open source R600c driver.
Another work-around for Kubuntu maverick:
Code:Workaround - not a fix Using the force - don't worry, be happy settings Editing the ~/kde/share/config/kwinrc. Before: Code: ... DisableChecks=false ... OpenGLIsUnsafe=true After: Code: ... DisableChecks=true ... OpenGLIsUnsafe=false ... Konsole: Code: LIBGL_ALWAYS_INDIRECT=1 kwin --replace The desktop effects are working...
I tried kde 4.5.1 yesterday and everything works with radeon gallium, including blur. But compositing is slow, especially when scrolling documents. On the other hand, Compiz is almost as fast as no compositing, i.e. really fast. The problem is that Compiz is a neat tech demo, but not so good a window manager, definitely not comparable to kwin. Also, there's some kind of simplicity and good taste in kwin's effects that Compiz lacks. I guess KDE people need to work on the performance side of things...
I got bitten by this last night, and it is worse than I expected. It's not just the blur plugin that's affected, and my drivers got blacklisted (for unknown reasons!) and I could not re-enable OpenGL compositing, while getting no error messages.
After deleting KWin config files and reconfiguring, everything worked. Including Blur. However, each change of settings crashes KWin, which is a known issue.
Looks like drivers get blacklisted way too quickly, and it is an annoyance. I do wish better communication between the KWin team and the Mesa developers in the future. Mistakes were made, it can't continue like this.
After setting it up properly, though, KDE 4.5.1 simply rocks. I've never used such a slick, enjoyable and user-friendly desktop anywhere, including Macintosh.