Why can't i move a selection within a layer? This has to be the most persistent problem in the mac version that hasn't been fixed. With every new GIMP version i curse this bug.
>>hold down Ctrl+Alt keys and click-and-drag the selection. This makes the original place empty. A floating selection is created. The required key commands may differ on your system, look in the status bar to see if another combination is specified; for example, Shift+Ctrl+Alt.
This does not function on mac as far as i know. You cannot even manually do it in the selection options.