So the reason that those commands are disabled is that since selection edges along the image edges aren't affected by those commands, those commands wouldn't do anything at all in the "select all" case, since *all* the selection edges correspond to image edges.
With the CS3 behavior, where feathering or shrinking modified all edges of a selection, even if they were at the edges of the image, correcting the resulting selection along the edge of the image requires hand-painting or hand-selecting those pieces that touch the edge to get rid of the unwanted shrinkage, smooth-age, or feather-age.
Avoiding the problem in the first place requires making the selection, then switching to quick mask mode, and using Filter->Other->Minimum... or Filter->Other->Maximum... or Filter->Blur->Gaussian Blur instead of Contract, Expand, or Feather selection. (I actually don't even know off the top of my head how to do smooth).
Any actions that modified a selection no longer worked properly if the selection touched the edge of the image.
So this is another one of those cases in Photoshop where the "right" way for something to work depends on which way you look at it. Are you trying to make borders with selection commands, or are you trying to modify selections of objects in your image that happen to touch the image edges?