This happens with images you originally imported into an earlier version of Aperture. Aperture 3 does not change the RAW processing for existing images in order to preserve their appearance. To access all the brushes and adjustments, select the affected images and choose Photos > Reprocess Masters.
If you want to reprocess all the photos in your library:
- 
	
- Click the Library tab in the Inspector. 
	
- Click the disclosure triangle to the left of LIBRARY

	

	 - Highlight the Photos icon.

	

	 - Choose Photos > Reprocess Masters.