Forgot these in my earlier reply; adding them for reference.
- Adding '-createconfig' to the commandline doesn't seem to make any difference to the behaviour one way or the other, but the config files are created as expected and look OK.
- After the first successful run, the 'cfg' directory is created. I tried symlinking this to /dev/null both before and after a successful run in case something in there was throwing things off; no change in behaviour.
- If running just the mamearcade64 binary with no additional switches (i.e., to force the UI to come up), there is an '___empty.cfg' (three leading underscores) file left in cfg/ . Not sure if this is normal behaviour or not since I don't use the built-in UI, but it only applies to a successful first run, not subsequent failed ones.
There are a couple of other things I'm not remembering right now; I'll add them if they come back to me.