This issue will depend on your computer hardware and software drivers, however sometimes when the issue arises you'll notice that the main viewport in AutoCAD will "expand" and "contract" by itself, which can cause other graphical errors within AutoCAD.  To avoid this error, simply do the following:

1. Turn off your layout tabs.  To do this, run the command LAYOUTTAB <enter> 0 <enter>.

This command will remove the layout tabs from your drawing, but will also avoid this bug from occuring.