I have a question... are you signing the new or old maps? If your using the new maps you must edit the map with whatever program you use and then close it. To sign it you have to use CMR. For the old maps you can just use dothalo to edit and sign them.
oh, well that's what i use all the time and i never had that problem, also sometimes when u ftp a map i doesn't transfer the whole map or maybe u messed something up while modding a map, make sure no other programs r running while ftping
go to http://ppfnoobs.net and click modding at the top then software! then download AIOv2 it'll have so many resigners thats what i use much better than cool spots!