I did try it with command line powermame and no dice.  The only other possibility I can think of is that in Johnny5 for it to work, the mame.exe has to be named mame.exe.  I tried using pmame.exe in the J5 setup, but, again, I still think it was a problem with powermame.  Could it be that the way powermame is reassembled has something to do with it?  I know that the way MikeQ compiled it caused the NeoGeo games to have a calender error.  Someone else recompiled it a different way and now they work.  The only problem is that the recompiled way is with Pmame32.  No big loss, except with J5.