Snort Windows - not working with ISDN Adapter

[MirkoMaty () t-online de (Mirko Matytschak)]

Hi there,

i have installed snort on WinXP and Win2K with Winpcap 3.0. It works fine on
the local ethernet but doesn't track any traffic on my Fritz ISDN card.
After dialing I get the IP adress with Ipconfig and enter it as HOME_NET
like that:
var HOME_NET 217.2.43.108/255.255.255.255
or 
var HOME_NET any

Has anybody an idea how to get that to work?
Mirko