If you zoom in I think the contours and provincial boundaries will show up, but at full zoom nothing shows because the national boundaries are missing. I am not sure exactly when they should show in mapsource, but gpsmapedit tells me they are not in the img file at all.
OK, I think what's happening here is that the file contains a lot of points that are so close together that the remove-short-arc process just throws them away and then throws the ways away because they contain less than 2 points. If you look at the diagnostics you get lots of lines like: 2010/02/23 14:49:04 INFO (Osm5XmlHandler): cambodia.osm: Way 200 (http://www.openstreetmap.org/browse/way/-2475) has consecutive nodes with the same coordinates (http://www.openstreetmap.org/?mlat=11.78333&mlon=103.63197&zoom=17) - merging node -187534 into -187526 2010/02/23 14:49:04 INFO (Osm5XmlHandler): cambodia.osm: Way 200 (http://www.openstreetmap.org/browse/way/-2478) has consecutive nodes with the same coordinates (http://www.openstreetmap.org/?mlat=11.78236&mlon=103.65167&zoom=17) - merging node -187581 into -187573 2010/02/23 14:49:04 INFO (Osm5XmlHandler): cambodia.osm: Way 700 (http://www.openstreetmap.org/browse/way/-2477) has consecutive nodes with the same coordinates (http://www.openstreetmap.org/?mlat=11.78327&mlon=103.34835&zoom=17) - merging node -187572 into -187564 and then later you get: 2010/02/23 14:49:09 INFO (Osm5XmlHandler): cambodia.osm: Way 100 (http://www.openstreetmap.org/browse/way/-11092) has less than 2 points - deleting it 2010/02/23 14:49:09 INFO (Osm5XmlHandler): cambodia.osm: Way 200 (http://www.openstreetmap.org/browse/way/-11091) has less than 2 points - deleting it 2010/02/23 14:49:09 INFO (Osm5XmlHandler): cambodia.osm: Way 100 (http://www.openstreetmap.org/browse/way/-11094) has less than 2 points - deleting it Can you reduce the number of points in the ways? Mark