Realplayer Converter converting .rm files into m4a files and not mp4

I have been successfully converting .rm video files into mp4 files for several months using RealPlayer Converter. Suddenly, RealPlayer Converter is converting the video files into m4a audio files rather than mp4 files. I attempted to re-convert some .rm files that I successfully converted to mp4s last week, and I'm now getting m4a files. I've tried uninstalling and reinstalling RealPlayer Converter. I've also tried this on 2 different work stations. I'm very perplexed.