PPTP problem with Linux Client

Hello.



I have a Debian Unstable Client with pptpconfig (as well as MPPE Support 
in the kernel).
This client can happily connect to another PPTP Server and can get the 
traffic routed.

But with the M0n0wall as PPTP Server I am getting the following log 
output after a sucessfull login into the pptp service:

Aug 10 23:28:22 erwin mpd: [pptpc0] LCP: rec'd Protocol Reject #17 link 
0 (Opened)
Aug 10 23:28:22 erwin mpd: [pptpc0] LCP: protocol 0x2145 was rejected



This message appears for every packet and no traffic gets routed.
I have m0n0wall running on Soekris net4801.



What's the problem, is there any solution?



thx,
 alex