I have Ubuntu 7.04 Feisty Fawn and Nokia 6610i conected through USB data cable CA-42. When I open xnokii, it tries to connect automatically to my phone. Program window becomes white and unresponsive (no buttons). Xgnokii does something but it takes much too long to do so - even if it's showing an error.
However, wammu v0.17 works perfectly with reading phone's agenda, last calls, SMS and files! Unfortunately Calendar and Todo list do not work at all: [I]Error while communicating with phone This function is not implemented for your phone. If you want help with implementation please contact authors. [/I]
Both xnokii and wammu are installed from repository.
Maybe Wammu is what you need, maybe not but I suggest you try it!