Yeah, I hear ya.  It just seems like right after a big fill the MM's will always test your resolve with a little tree-shaking and try to get those shares back from you a few pennies cheaper.  If you held you are still up 2-3 cents in 24 hours still though so no harm no foul.

It's why I usually go by a two bullet or three bullet approach.  If they pull that kind of tree-shaking stunt I am ready to nail them for more shares at the lower level they bring it to.  :)