asterisk users - Aug 2005 - Asterisk on VMWare 4.5, Error Ouch ... error while writing audio data

I' m using Asterisk 1.09 on an virtual pc (VMWare 4.5) for testing. I can
make calls from a Softphone to softphone, Hardphone to Softphone and so on.
I can hear both RTP Streams. But when I call prompst on Asterisk I can hear
nothing. RTP Stream goning from Phone to Asterisk but not the other way. I I
start the PBX for console I got an error 
[app_rxfax.so][root@asterisk1 root]# Ouch ... error while writing audio
data: : Broken pipe