I tried the hack as listed and have had some issues I thought I would share with everyone here.
The first time I tried the hack it totally screwed up the keyboard and I had to use the remote to get the player back to normal.
I've applied the hack a second time after some more reading but the menu options are severely limited compared to the original unit. The biggest difference is a complete change in the menuing on the unit after the 'hack' has been applied resulting in nearly all the menu options disappearing.
I'm wondering at this point if there has been any more research done regarding the use of the hack on the 510 series.
Still new to MD but I've already ditched the mp3 and music stick players w/ minidisc and I'm NEVER going back.