The net.ppp0 script should call pppd with with ipparam ${PEER} instead of ipparam ${IFACE} since it already supplies linkname ${IFACE} and pppd scripts can access it using the $LINKNAME env variable, while there is no similar access to the peername if not passed as ipparam.
fixed in cvs. I didn't make new releases because users aren't usually interested by the 6th param of the ip-up/ip-down scripts.