This concerns traceroute-1.4a5-16. When I use traceroute -i ppp0 url, traceroute uses sl0 ip adress, not ppp0 adress. traceroute -s <ppp0 ip.adress> does work.
So what your saying is that you have two interfaces up, a sl0 and a ppp0 device and that if you specify the ppp0 it will use the slip device every time or am I wrong?
This problem appears to be resolved. Please reopen if I'm wrong.