Looks more like a problem with the contacts on either the Hucards being used or the system..
Your first step really ought to be just to clean (and seriously clean) both cards & contacts well. Then do a little fidgeting & cleaning with the port itself.
Either that, or leaky capacitors could have leaked on to the board... in which case, the board may need cleaning (and possible capacitor replacement, as well.).
A good bit of cleaning goes a long way to help your system... as does dirt to do a lot of damage.
Good luck!