Just to add to this, as I was experiencing the same issue on my arcade machine...
The above solution works, however there is a quirk, and I noticed this playing against the CPU in 1-player mode. When AllowDebugKeys is set to 1, it appears that the space bar is mapped to a debug function, specifically re-filling player two's health bar. It took me a minute to figure out what was going on, as I was clearly beating the snot out of the CPU player but for whatever reason their health bar kept re-filling. I have HK mapped to space bar, so I thought maybe it correlated to some debug hotkey, and sure enough I found that every time I pressed HK my opponent's health would refill.
The solution to fix this problem is to simply change AllowDebugKeys back to 0 while leaving AllowDebugMode to 1. Hope this helps someone!
