Shift click does not work. Moving items is very difficult. No right clicking for half stacks.

Shift click does not work. Moving items is very difficult. No right clicking for half stacks.
when i click on an item, i expect it to stay on my cursor until i am ready to drop it by clicking the mouse. Instead i must hold own the mouse button, and once i release it, if the item isn't perfectly lined up with the grid, it jumps back to the original spot it came from.
furthermore, because of the previous issue, i cannot right click for half item pick up. it simple does not work. when i right click an item, nothing happens.
1.6.2 OSX
I started in survival mode. i started a new creative world and it did the same thing.