I have some drawing formats (templates) that I created at another company and updated them for a different company. 

There is a logo on the title block that I deleted and put in the new one as well as updating all the relevant text.   The text stays consistent, but the logo keeps reverting to the old one even though I had thought it was deleted and put a new one in. 

The drawings have been working fine for months and then today started doing it again!!??

Any ideas?