Isn't stacking suppose to help get a sharper close up of an image?
You got a lot of detail, but its really soft.
I personally like to see a bit of background around a close up like that..but that's just my preference.
Here is a link to "focus stacking"...im not sure if its the same as what the OP was doing though...
[ame]http://www.youtube.com/watch?v=fJiEw4VCcYU[/ame]
Stacking is used in macro photos because the DOF is so shallow. It is a number of different pictures taken with slightly different areas in focus so either the entire image is in focus, or the entire subject, rather than just a small portion.