gta02, debian, fso: fr does not stop to ring

[arne anka]

just tried, what happens when zhone does not run and a call comes in.
the phone vibrates and plays that horrible sound -- and does not stop!
even when i hang up at the other side the fr still vibrates and makes  
noise.

i managed to start zhone -- but the buttons to hang up are gone and no way  
to kill that ringing anymore ...

anybody experienced that and knows
a) where to once and for all disable that sound (a configfile, a flag a  
global variable since that sound file comes again like a bad food)
b) if there#s fix/workaround?
c) where to kill that ringing? i can't reboot everytime