Problems with multiplexing to SFD

[Prince_of_Peace]

I got a problem with sfd files.

What I wanna do is to de-mux a sfd file into its audio and video files, change the audio and leave the video unchanged. Then make a new sfd file with the new audio and the untouched video.

I de-mux the sfd with "cube media player 2" and i have several options in deciding what kind of output I want, so i just choose an MPG and the WAV.

Then I alter the wav file and i wont change the sample rate or the bitrate.

Now I've got both my video and my new audio file. For multiplexing these two, I use "Sega Dreamcast Movie Creator" with it's multiplexer version of 1.07. The output I get from it, is an SFD file with strange audio specifications :
Frequecy: 469963268
Channels: 1 (thou i had a stereo file for MUXing)
Rate: 939926536
!!
and it wont be played it cube media player any more, with an error saying "Create Buffer Failed". What have i done wrong?

I would appretiate any help