Copy from one folder to another on the remote server?

My problem is that I cannot copy some files from one folder on remote server to another folder on the same one. I have to download it first and then upload it.

This is what happens: I open a folder on the remote server and select one or more files then right click and click copy, then I open another folder and right click but "paste" is grayed out.

Any suggestion?

SOLUTION: Open a second session with same server. Copy from one session to the other. Then hit "Refresh" on the second session to see the files have been copied.