Before spending ages trying to get the other stuff working it's nice to just verify that the data cable/IR connection is working and you're permissions are such that you can communicate with the phone.

SCMxx is a clever little program which for nearly all Siemens Phones above and including the X25 series can download/upload SMSes, Addressbook entries, the SIM-based Phonebook, calendar entries, files, images, midis etc. It's available in rpm, tarball, etc and it's in the Debian stable package repository.

Anyway, having installed it you can test connectivity simply with:

gavin@linux gavin> scmxx -d /dev/ttyS0 --info