The vgm player crashed on the real hardware at the first dac sample. The vgm files generated by vgmmaker appear to output dac samples before a seek command. It was assumed that all files would seek before a dac event and the previous contents of the dac indexing register was the control port $C00000. It seems that reading a byte from the control port crashes the real hardware. This problem was fixed by initializing the dac index register to the start of the dac data block.
This little program will patch vgm_play.exe V3.10 to fix the vgmmaker problem
http://mjsstuf.x10hosting.com/SEGA%20DEV/VgmPatch2.zip
The contents of this thread suggest that there is a problem with the rom builder, and yes its full of bugs and needs rewriting. I stubbornly decided to try and write my own gui programming framework so now the rombuilder is in a terrible state. Drag and drop is broken but adding files by clicking on the button works, I could not find any problems with the rom builder in relation to these vgm files.