what is the file called that you are editing? it sounds as if you are editing the compressed files and not the original uncompressed css files.
in that case, always remember to switch of any file compression such as rokgzipper, rokbooster, gantry gzipper etc and only to edit the original css files.
yes, that is a compressed file and should NOT be edited.
please disable rokgzipper, rokbooster, gantry gzipper etc and ONLY edit any files located under
/templates/rt_maelstrom/css/...