Global Mapper v25.0

extremely slow out of no where

Hi, 

I've been using global mapper V20.0 for over a year now, no issues.  I downloaded and installed the newest version recently just to give it a try, but uninstalled it earlier today because my V20.0 is so slow it's unusable now.  I took a screen cast of what it does when I try to draw a simple line on a small DEM: http://gofile.me/50AXz/EtxunleOd.  Again I have no idea what's caused this.  I thought maybe installing the new version of GM was the issue so I uninstalled it, but the issue persists.