knoppix@hal9000:~$ ls -la /etc/ppp/peers/dsl-provider
-rw-r----- 1 root dip 1810 Aug 7 20:47 /etc/ppp/peers/dsl-provider
knoppix@hal9000:~$ ls -ld /etc/ppp/peers/dsl-provider
-rw-r----- 1 root dip 1810 Aug 7 20:47 /etc/ppp/peers/dsl-provider

There seems to be a permission problem!