memory card problems

im using a flash card to load samples from my Mac via the USB cable, the computer says i have 1.82 G available for memory however when i try and add more samples it is displaying a message "the item ... cannot be copied because there is not enough free space" this doesnt seem right anyone have any suggestions what is wrong??
i have the 128 expansion fitted to my MPC 1000

Hook it up via USB to your Mac en than empty your trash.

Or maybe re-format.

thanks a lot the re formatting it seems to have solved the problem