You mean Canon EOS-1D X?
That camera is supposed to be supported by Aperture 3, see the list of supported cameras:
This camera has been added to Lion by the "Digital Camera RAW Compatibility Update 3.13", have you upgraded your system to the latest version? You also might try to install the raw update
from the Apple support page: http://support.apple.com/downloads/#raw%20update
Is it only Aperture that does not see the raws? Can you import them in iPhoto or Image Capture?
thanks very much,
I was not able to import them into iPhoto either but now I've done the
and they are now visible in aperture and on the macs in Finder.