thank you very much for your help.
another two questions if you someone could...
1. nothing happens when i try connect the phone to laptop via usb (so i could copy the contents of phone memory). the option whether to connect as usb storage or suite doesn't appear, is there a command on xterm to force the device to connect in usb mode or a command to make device use mass storage mode as default?
2. is it possible to flash only the operating system, so that documents and pictures remain in memory?..