ppp problem.

hi, I have a PPP problem:
at window98,my ppp get ISP’s Opt is:
ip 61.158.203.13
gateway 61.158.203.13
every thing is ok.

at QNX,my ppp get ISP’s Opt is:
ip 61.158.203.13
gateway 61.158.206.36

so, if I ping ppp0’s IP or gateway at ISP, it’s good,
even ping www.qnx.com , can resolve IP,but cann’t response.

how can I do it?