Not that it matters but the OP's statement here...
...If I use the Move Tool it just moves what I've got selected in the box...
...suggests to me that the 'New Selection' tool MUST have already been selected.
As Sam pointed out, any of the other options do not allow moving anything.
If the OP had carried out my suggestions in post #3 the problem would have be solved there and then.
I assumed they just that missed the 'important' bit which is why they were still having trouble.
From the sounds of it the OP has got trigger happy and has been changing stuff without notifying those trying to help them....
...Now I have 'New Selection' selected I can now move the box !!...
If any of the other options were selected then the OP's previous statement about 'moving what I've got selected in the box' doesn't ring true.
Like I said....doesn't matter now, but it most certainly could have been done and dusted a long time ago.
Just saying.
[gets off soapbox]
Regards.
MrI'veGotNothingbetterToDoThanArgueTheToss