ppp server on QNX

Maybe somebody has some experience with developing dial-in ppp server on QNX
6.1 using null modem?
We have almost done everything here and when connecting from another QNX
box to dialin server everything works fine. The problems begind when
connecting from Windows box. On server we start pppd with command line:
“pppd /dev/ser1 115200 passive nodetach connect ‘chat -f /etc/ppp.in’ netmask”.

Contents of /etc/ppp.in:

The first connection goes well, but when hanging connection from windows and
giving second try - it fails. For reconnection it is required to restart
pppd but it seems, that pppd does not notices link termination and does not
terminate execution (when connecting from QNX eveything is OK). Maybe some
settings for /dev/ser1 are required?

Best Regards
Jonas Zaveckas