The Siemens M65 Cellphone is more or less working with Linux. Here are some hints how to use it with it:
The M65 has some variants. Mine is variant A112. You can find out your variant by entering '*#06#”, push the 'More' button and scroll down to 'Variant'. There you can although see the firmware version. Be sure to have the newest one! Check on Siemens Mobile for the newest version.
Some things about the cellphone that are not directly connected to Linux, but very useful.
This report is listed at TuxMobil - Linux compatibility guides for laptops, notebooks, PDAs, mobile phones and GPS devices