I have an LG Dare and have the same problem. My dealer told me to get a different phone that was BMW compatible. You don't need a new TCU or have to disconnect the battery. There are three fuses for the NAV and phone in the back right corner of the trunk. With the X5 off, take the fuses out. Start the X5. Nothing will come up on the NAV screen. Turn it off. Put the fuses back it. When you start it again it you will have your phone back. You will need to do this whenever you lose the phone. May be a little pain, but it's a lot better than getting a new phone or TCU. Good luck.