I am working on a map of France based on Open IGN, OSM and other sources.

I have broken it into tiles 0.25 latitude by 0.5 longitude.

I built a set of contours using 'marching squares' on the IGN Height data..

But MKGMAP fails on some of the contour tiles saying 'Too many roads' (which I guess is really Too many Polylines). Is this a limit on the number of Polylines (I could join some shorter ones together) or a limit on the number of data points?

Thanks,

John