I've tried to convert the recorded real media .RM file with Total Video Converter, Xilisoft Video Converter, MediaCoder and Replay Converter with no luck.

However old nice freeware software Streambox Ripper did the job perfectly.

Also I had no any problem when converting the recorded .RM to .MP3 with Cucusoft Ultimate Video Converter.

Either get an audio/video converter that works or keep bugging the developers of your favorite converter so that they support this conversion.