Test your card on another type of recorder before you chuck it! I have reported on my experience with the MT 2496, which I think is flaky in how it handles CF brands. When I first got the machine, it worked fine with my Sandisk Ultraa II 8GB card. I didn't use the MT much, but upgraded the firmware regularly. At one point I used it, and found that I was getting a periodic clicking maybe four times a second when I ran it at 24/96 or 24/48, but not at 16 bits (even 16/96, so not likely a speed issue). M-Audio blamed the card, but when I tried it in a Fostex or Marantz at 24/96 it worked fine. However, a new Sankdisk 8GB card and a Delkin 8GB card did work correctly in the MT. Go figure. With the last firmware upgrade, I again tested the original card and it seems to work fine again. I stress that the problem was not intermittant, the clicking occurred every time at 24 bits, and then went away just as completely with the new firmware.
Jeff