"**** leaked ****" is your problem. You have a hole in your map somewhere. Your map needs to be "water tight" and not have any entities outside. In bsp, you can do a file|leak check to help you find leaks in the map. What you're doing when you export is compiling the .map into a .bsp. You shouldn't need to convert a .bsp into a .map. Not only will this generate a messy map file, but if you don't have the .map source and permission from the author of the map, it's likely a copyright violation and can be considered theft.