I've been having this problem for at least a year. I just broke down and paid for a scanner app today. Amazingly the scanner app prompted me that I had too many apps running using up too much virtual memory. It warned me that it would crash if I tried to take any pictures. I tried anyway and it crashed. I then tried Evernote and it crashed too. After closing out all of my other apps I tried the scanner app and evernote again, and they both worked. I'm going to keep testing this, but closing out apps to free up more memory for Evernote seems to do the trick. Hopefully this works so that I don't have to take the added step of uploading docs/images from the scanner app as pdf's into Evernote.