Currently Being ModeratedFeb 2, 2013 9:17 AM (in response to MonsterMash)
See Jeffrey Jones post here: Re: Aperture (3.4.3) not exporting changes made to the image?! and look at article he is pointing to.
Which "sharpening" brush are you using? The "Edge sharpening" brush in the regular adjustments, or the "Sharpen" in the "Quick Fixes" menu? The Aperture manual recommends to use the "Edge Sharpen" adjustment. The "Sharpen" brush is kept for compatibility reasons with Aperture 2. Edge sharpen gives better results.