BUG: When no elevation is available from DEM, returns a default elevation of 0 (instead of nan, which is ossim default value)

BUG: Ensuring that the update() method is called on ossim internal projection everytime a parameter changes

BUG: Fixing a bug that prevents the EPSG code to update in some cases (like changing UTM zone for instance). Patch submitted to the ossim mailing list

BUG: Fixing odd strestreaming behaviour. The largest possible region was requested once before atually streaming