Possible Navigation computer problems: MKII or MKIII?

[X5-4-Fighting]

Hi everyone,

I may have a problem with the navigation computer (with DSP) on my 2001 3.0i X5.

I just noticed recently that the 4x3 display would flicker in sequence between the main menu screen, a blank/black screen, and the radio station screen. I also noticed that the radio or CD would stop playing and/or the nav/radio buttons would lock up.

I did search the forums for similar problems (one started by KP1 under the thread "Navigation failure: First intermittent, now not working at all"), therefore I'm assuming that it is also a problem with my nav computer.

I have a couple questions I hope any of you could answer:

(1.) Is it safe to assume based on similar experiences that it is a problem with my nav computer? Or is it my battery? or a bad fuse?

(2.) I think I have the MKII based on my year and make, but would the MKIII be compatible with my X5?

(3.) Can anyone in the general Los Angeles area recommend a shop that could offer a replacement computer- which I would assume would cost much, much less than going directly to the dealer for this type of service/replacement?

Thanks in advance for any and all responses!