This is exactly the same problem I have with MacOS 10.5.0, beta build 2114. When started, Evernote works reliably. If the machine is left for a lengthy period (for example, overnight) then when Evernote is used the next time, this problem emerges. Presumably due to the machine going into sleep mode. The screenshots from SunscreenAl and JackFritz show the problem accurately.
I'm a software developer by profession. If anyone from Evernote would like to pair directly on this problem to investigate it on my machine and understand it I'm happy to do so. I'm also happy to supply log files if that is useful.
We'd all really like this fixed. Particularly those of us paying for Premium accounts!