Canon 5D is supported by Aperture 3 and the raw processing . What exactly do you mean by
Aperture 3does not recognizethe pictures of my5D
Do you get an error/diagnostic message, eg. unsupported format, are they displayed with "exclamation point" badges, or don't they display correctly?
Have you tried to reprocess the master images to force a new raw conversion (select the images in the browser and use the command Photos -> Reprocess Masters)?
Butsince2 daysAperture 3does not recognizethe pictures of my5D
What happened two days ago? Did you install other software? Did you experience any crashes, failed hardware recently?
Can you import your raws if you work from a different user account? Eg. the Guest account? If the problem only occurs when working from your account, you probably have corrupted preference settings. Then move your user preferences to the trash as described here:
Aperture 3: Troubleshooting Basics: http://support.apple.com/kb/HT3805
Regards
Léonie