kppp cannot find /dev/modem

Hi, I recently installed 10.1 I use a modem to connect to the internet, and I configured the modem using yast. I use kppp to dial-up. However, after rebooting, I always get the error "kppp cannot find /dev/modem" To rectify this, I launch Yast, use Network Devices | Modem | Edit | Next | Next | Next | Finish. I change nothing. Then I go to Kppp again, and it dials and connects fine! What is going on? John