I was #42 post on this thread. At the same time I posted, I also communicated with Evernote's support. I gave details of my system, Evernote application and issues (which may not be yours, of course.) They quickly (next day, which was on Sunday) sent clear instructions as to how to uninstall, and reinstall a previous version. Took less than five minutes. Solved it all for me. I am fully functional once again, as far as I know. Thank you, to Evernote's Support team!
I have had no problems with Evernote until I updated. I am on Mac OSX 10.6.8. So far I have discovered that screen captures aren't working. They are listed as recent notes but won't show up in notebook. When I restarted Evernote they were lost permanently. Also, my Evernote won't sync at all. So, I am quitting using my desktop Evernote for now, until another update fixes these.