I am working with AutoCAD 2014LT, last week I was having an issue with drawings reverting to older versions without any reason. We reset the program and that problem seems to have gone away. Now when I switch between layouts it takes a solid 10 seconds. If I modify text in a block it takes about the same to show the change.
These are really tiny drawings (like a fresh template) and I only have 1 open. Like I said, I did not have this problem before the reset so it has to be a setting that changed.
Also, CAD prompted to save customization so I did... when I tried to go back the zip file where the files were supposed to be saved was empty.
I have set animations to zero or off.

Windows 7 Pro SP1
32 GB RAM
AMD Radeon R7 250
AutoCAD LT 2014 SP1

Before you say it, LAYOUTREGENCTL does not exist in AutoCAD LT 2014. Neither does the "Layout Regen Options" under Options/System.