1998 750il Navigation Problem

[4ap]

I seem to have problem with my nav unit. Whenever I put the Nav. CD, the navigation screen (which also controls, radio, cd, and phone) starts resetting. Meaning, it turns on gets the menu, and then repeats the same thing over and again. If I pull the Nav. CD out, then other functions work without the gps navigation.

I would like to get some help especially if you experienced similar problem and how you went about getting this fixed. I am considering replacing the CD, but that according to Navtech is not the problem.