For DAB traffic in Belgium you need also:

Database for FM Traffic Providers software up to version 3.70
as of July 8, 2013

Use myDashboard to install this file.
http://www8.garmin.com/support/download_details.jsp?id=4427
(279 KB)

Change History
Changes made from version 3.10 to 3.70:
Add support for Digital Traffic in Belgium, when the unit has compatible software and the traffic receiver has a subscription for the service.
...

[Only registered and activated users can see links. ]