There is a problem with Excel 2013 with macros running where thay do a lot of things. Screen flickering and slow performance are the symptoms. There have been some recommendations, marco wise, that might reduce the flickering and speed things up. The 1.7.1g version has those changes. Itis the same as 1.7.1f version, just with those recommended changes. I am running 1.7.1g on my 2007 with no problems.