I'm pretty surprised the VGA monitor you were connected to at the beginning of video 1 was able to digest a 15KHz signal..  My suspicion is that something is effed up with the Soft-15KHz install.  I don't think you're sending a 15K signal.  Have you tried uninstalling and reinstalling it Soft-15KHz?  What graphics card are you using?  The resolutions listed in quickres seem awfully limited.