How do I turnoff selective sync

I have selective synch set up on one computer, but only wanted to do this as a temporary measure.  I'd now like to have all dropbox folders automatically synched on this computer.  I've read the thread above.  If I create a new folder on that computer it will auto synch. But what happens if I add a new folder on a second computer that is not set to selective synch.  Will I always have to remember to go to the second computer and manually check those folders from now on?  Seems like there ought to be an easier way.  Can I unlink dropbox on the computer with selective synch and then link it again and do not select synch the second time?