I had the same problem starting on Friday 19 Apr 2013 and called them and I was told to update Java and compact my file. Then I called on Sat. 20 Apr 2013 because still I can't merge. Sunday 21st, still no change, finally they admitted it was on their end. I haven't called today, but if this keeps up, I am canceling my membership. This is ridiculous for the price we pay not to have full use of the site. I am fed up.