Navigation system gets lost on map

[afnetman]

I have the MKIV Sat Nav in a 2004 X5, it had been working great most of the time up until a few months ago. Now I have noticed that the system gets lost on the map and does not follow the road. I know I am on the road but every now and then the tracking on the map shows me off the road and the system asks me to "Please follow the planned route" It does eventually will fine the road again only to get off track again. Sometimes it even shows me in a different town.
I am running version 32, and have the new high European 2011 DVD that is dual layered. Not sure if this is the problem as everything I have read states that the system after the upgrade to V32 will read DL DVDs and I can see that the system is reading the map.
Does anyone have any ideas or have you had this same problem? Thinking of replacing the SAT Nav with a TOMTOM if this keeps up.

Thanks Jay

[KiwiJochen]

Likely GPS antenna gas failled. Go into service mode and look at the GPS signals Report back here.