i'm already install SuSE Linux....
the problem is about my modem... I cant connect to internet....
im using Aztech 56K USB Port.....
for ur information my Suse Linux using kernel version 2.4.10 and I already upgrade to version 2.4.18... and the problem is the same and message appear .......
"pppd:failed to open /dev/ttyACM0 :invalid argument
pppd died:serial port open failed (exit code 7)"

pleased help me////