When you say "cannot" do you mean you literally can't crab them or that it is just an incredible pain in the ass and difficult to control them when you do? If it is the latter, I completely agree. However, if it is the former and you literally can't pick them up then something is wrong. Have you remapped your keys so the Z key is no longer set to "grab?" If not, are you holding the key down whilst you are attempting to move? I do not want to insult you here as it sounds like you have played Oblivion also and have a good grasp (no pun intended) of things but you do realize that the grab key must be depressed while trying to move objects, correct? I always remap some of the less well positioned keys myself. I made "F" the grab key and it becomes much easier to manipulate the correct series of keys after some practice. It's still a pain in the ass but it does make things easier.