When I downloaded the new European (nonrouting, Garmin-img) map from Computerteddy, (version of Aug 1), I found out, that the Danube river is mapped only as a polyline from the Serbian-Romanian border on (city of Ram), not as an area any more. This is new, as my former version still has it (more correctly) mapped as an area (in addition to a polyline - the river has a width of about 1 km there).
Is there a reason for this ?
Where do we post, if OSM objects disappear ?
Is the river still mapped as an area in OSM? Can you give a link to it on the map (use the permalink option).
If its still mapped correctly in OSM, it suggests something has changed in the processing/generation of the Garmin map. You could contact ComputerTeddy and ask, or try using some other OSM Garmin maps.
If its no longer mapped as an area in OSM, you can check the history and find out who changed it. You can contact that user and ask why it was changed. It might just be an error that broke the rendering.