The presentation styles (background images on the master) is then corrupted and I have to copy and paste the slides into a new presentation to reformat.  This happens very frequently.   I just moved to 2013 from 2010, where I did not have this problem.

The files are local on my pc.  All presentations do this.  It is driving me crazy.

Based on my research, this behavior could be caused by some 3rd-party applications. For example, some anti-virus software, and certain file backup system in a recent case.

So, have you also installed any other applications when you upgraded your Office 2010 to Office 2013?

Try configure your computer to reboot in clean boot mode to help determine if this behavior is caused by the 3rd-party applciations & services.