I am having the same problem accessing the SetHTML and GetHTML when the editor is on a hidden TabPanel after a postback.
I can populate the editor in my codebehind, but cannot access on the client end with SetHTML or GetHTML.
This is starting to be a deal breaker for us. We are still working on other options. I really like this editor and do not want to research another one, but may need to if there is not a workaround for this problem.
Is there another way to access the text?
The Analytical Group