CF Card Troubles

Hi, I need some help with my CF card. I want to transfer mp3's to it fast...I have a usb 2.0 connection and a usb 2.0 card reader. For some reason when I take the card out of my axim and put it in my reader, it doesnt work. It doesnt detect it or something....I tried a different cf card that was not in the axim and it worked fine...Could it be the formatting or something? Some help plz :rolling:

That's weird. What brand of CF are you using?

I am using a Memorex 256mb CompactFlash