Hello i found out that Nasa SRTM files are available for download. I download a DEM file from here:

http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/e020n90/

However after unzipping the file to a single DEM i have an error that says "Only accepted meters or arc-seconds unit for xy!"

Could you please explain what i need to do to use this file. Also! When i load the OpenStreetMap-Cyclemap.IMP i see contours but when i export it to Aventura i see no contours. How do i get 10/50/100 meter contours on my open cycle maps please? Is there a work around such as a pdf that i can imprt and set the coordinates such calibrate a map from image? I really need the contours. You OpenStreeMaps dont seem to come with them. How can i overcome this without using unfriendly programs such as Mkgmp and the like?