Any ideas as to what is wrong???

[jonack]

BMW service doesn't seem to know, at least up to now.

Once in a while during the past six months, a SOS light would appear when starting the car. (It looks like an anchor with a cord wrapped around it.) The NAV would simultaneously freeze... no communication, radio, or means to navigate at all. Usually the system comes back within a half hour. BMW service thought they had it solved.... they didn't, happened again this morning.
Any ideas?
btw: I decided to go with the the first level of extended warranty: powertrain, for two years..... $1800.00