gtkgep & stompboxes2 on FC2 - microphone recording

Hi all!

Back from my vacation, I tried my new guitar and plugged it into
the microphone input. The sound of the guitar is there, but
I can't get gtkgep or stompboxes2 to work.
In GNOME I opened the Volume Control and clicked "rec." for the
mic, but that doesn't seem to work.

Anyone uses gtkgep or stompboxes2 ?
How do I set the microphone input to recording, so that the effects
from gtkgep or stompboxes2 are enabled ?

Thanks a lot in advance!

Cheers,
Hannes.