Hi,
could it be there are 2 people sharing the car and you keep moving the seat back and forth, what happens is that there are 2 wires underneath the seat that go into a connector, with the seat going back and forth these wires become dislodged in the plug, you have to pull the plug apart and make sure it goes back tightly together, provided you have the radio code , you can then disconnect the battery, which should reset the computer, failing that it will need to go on a code reader and hopefully just have the codes cleared
Paul Bale
May 2008