Since Lion upgrade, I have the same bug with Photoshop CS5 Mac :
http://forums.adobe.com/message/3930635 (read only)
When I double-click on color stops in the gradient editor, sometime it opens the color picker, sometime not.
Is there a solution for this ?
The top two stops in the gradient editor are opacity stops so they won't open the color picker.
Double clicking on one of the bottom two color stops should open the color picker though.
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