CF cards not mounting

My CF card never mounts in Finder, disk utility, the desktop or in image capture. I'm not 100% sure about this but it seems to have shown up after I upgraded to Lion 2-3 weeks ago with the iOS5 release.

Aperture will show the camera and CF card but only lets me import (random # of photos) then it fails to import the rest. I have to quit, re-open aperture or turn the camera on and off to get all my photos loaded.

I can not understand why this is suddenly giving me all these problems. The card works perfectly in the camera so I don't believe the cards gone bad.

Using a Canon 50D and Kingston 16gb CF card.

Thank you to everyone who helps.

So here's the update... I still need help.

I connected the CF card to a MBP, running 10.7.2 like me, and transferred the data to usb drive. So the CF card CAN be read by a Mac on Lion. But mine doesn't see it.

Now I have my pics and stuff and end up repairing permissions, resetting pram and something where I unplug the computer from the wall and hold the power button for 5 sec. Nothing fixed it. On the phone with Apple for over an hour now and they are stumped too.

WTF is wrong? I've tested all the hardware on another Mac and it all works fine. So what software am I missing?

Oh, and I reformatted the CF card in my 50D three or four times to see if that could fix things... nothing.

Is there a way to force a drive to mount from terminal? I can't understand one computer working and the others not. This is ridiculous. 🙁