I hope somebody can help as I am having a great deal of difficulty tracking down a problem.

I have a 2001 X5 with a Mk-3 Navigation system with the 4:3 monitor.

Sometimes when I turn the ignition on for the first time that day, I cannot change the Mode of the monitor display. It seems to get stuck on what was used when the system was last shut down. In addition, none of the buttons work, although, you can adjust the radio volume by turning the left knob. Similarly, the steering wheel, only adjusts volume, but cannot change radio stations. When selecting the GPS with the knob, the menu comes up, but although you can scroll through the various choices, you cannot go any further.

Basically, I am stuck with one radio station and no GPS.

The strange thing is that after an hour or so, everything starts working correctly and I cannot replicate the problem.

The last time it happened, I noticed the following with the Navigation Computer unit:

1. The Red power light was on, even though there was no key in the ignition.

2. I heard a soft whirring noise from the unit. I removed the Nav CD from the unit and drove around, but again it made no difference. The unit was still stuck.

Any idea's on what is the likely cause is greatly appreciated. Could a faulty Navigation computer create these problems?

Regards