I had a similiar issue on a partners mpc ... you really had to pull to get the cards out. So I looked down in the CF slot and one of the pins was bent out of shape.
The unit worked fine ( i guess that all of them aren't used...and he was lucky ), and the pin didn't break, it just sorta wedged in under the card when It was in the slot. The only problem it caused was when switching cards back and forth from the CF reader on the computer.
It really bothered my buddy, so I took a flat butterknife and gently lifted the pin up into place and then put a CF inthere to straighten it out. no problems since. We use Pony, SanDisk, and a couple cheap-azz that have the label worn off.
(btw: I couldn't stand having to unplug the usb to get back to working after transfering sounds from the computer, i felt like I was gonna work the port loose...I went to the store to buy a USB extension cord to wear out instead, but bought a card reader for $11 and love not having to stop a beat just to transfer)
