Hi there,

I'm using a Mac mini (Core Solo) with the latest online updates of OS X (Kernel 10.4.7).

For some days now the function keys (F1 to F12) of my keyboard are not working anymore.

Any ideas, how to troubleshoot that problem?

Roger.

If you goto System Preferences > Keyboard there is a checkbox that toggles using the F-keys for "hardware features" or "software features" ...

I think you want the latter. Make sure the box is checked so that it controls hardware features on your mac.