can't change a dim by using + or - keys in 2013

Message was edited by: Jeff BurgessLet me give you an example: in SW 2010 if I had a dim that was 22.5 and I needed to change it by .1875, I could click behind the dim in the dim box and put -.1875 and get the dim of 22.3125. In SW 2013 I can't do that and I didn't know if this was a setting issue or if this is not available now in SW 2013.ThanksJeff