Well it actually 'works' it just became invisible!

I press Alt + F2 and nothing appears on the desktop, but it is listed on the taskbar.
And even though it is invisible it has focus and I can type and run a program.

In ~/.xsession-errors it shows:
QPainter::begin: Cannot paint on a null pixmap
QPainter::end: Painter not active, aborted

Using KDE 4.1.2 openSUSE 10.3

Any ideas?
Thanks!

There's a thread on the Suse forums about this and iirc it's a bug with the desktop theme you're using, try changing to Elegance and restarting KDE4 (you must restart for it to show again).

Google for "Alt + F2 not working anymore" and you get information

http://www.google.de/search?q=Alt+%2B+F ... =firefox-a

it seemingly randomly stops working for me too on opensuse 11.0 with the default oxygen theme.

if it's randomly not showing, it's usualy a video card driver issue; if it never shows it's a desktop theme issue.

you don't need to restart your whole session to see the changes, though, just: "kquitapp krunner; krunner" will do. eventually we'll propagate theme changes automatically to krunner as well.

I think that's trouble with your desktop's effects settings. Try to Off them