412 in 1 Rebooting at game selection menu, games themselves work fine?

[WilkyWorld]

I just installed the 412 in 1 Game Elf card in my bartop. I followed the special notes on wiring for this board and made sure pin 27 wasn't connected to ground. The system boots fine, and once a game is selected and started everything works great...and can run for hours that way. However, when scrolling through the games list the Game Elf will frequently reboot. I've noticed that the reboot usually occurs when the scrolling stops on a game and the game details/graphic are being displayed. I can't make it through the full list of games without the system restarting. Here's what I have checked so far:

1. Wire on Pin 27 is cut and terminated - NOT connected to ground
2. Wire on Pin 28 is used for ground, and according to the manual this should be ok?
3. I checked the SD card, and while it appears very loose (can be pulled out with little effort) it appears fully seated. Can't imagine that the card should be this loose though.
4. I checked voltage at the power supply before and after the Game Elf was installed and it reads at a near constant 12.05 volts
5. The -5V is not connected nor used in any way
6. The system and IO test works well, and doesn't report any other controls on (outside of P2 start, no P2 controls for joystick or buttons are used)
7. It doesn't seem to matter what game I stop on...it appears somewhat random when the problem happens. I can scroll down 50 games one time before it restarts, and it could take 9 games the next
8. There is fan cooling throughout the cabinet and the temperature is not a problem. This even happens when the cabinet is cool and just starting up

I could understand a broader system problem is it restarted at different times and while in games. It just seems like more of a SD card issue - like it tries to read from the card and has an issue so it restarts? I did some searches, and came across a few examples of where the board constantly reboots and the fix for them was a loose SD card. While I suspected that, re-seating the SD card did not help me.

I would GREATLY appreciate any suggestions. I put this bar top together for my son's 13th birthday and want to get it working correctly. If need be, I'll order another 412 in 1 and possibly another JAMA harness to rule that out as well. Thanks!