Edit Page Blank

When I try to edit any pages the Visual editor doesn’t show any content, the Text editor can’t be clicked, and it says there’s a word count of zero. However if you actually view the page there’s content there, and if you highlight whatever’s in the Visual editor you see white HTML text.

I disabled all the plugins and the editor works. Through trial and error i found that any user-ish plugins cause it to happen again. In other words the plugins Simple Login Log, Simple Login Redirect, User Access Manager, and User Login Wiget all seem to cause the problem.

None of these plugins are created by the same person. I tried a different redirect, Peter’s Login Redirect, and got the same problem again. It doesn’t seem to be the plugins but something they all have in common that seems to be the issue, and they’re all used when a user logs in.

Any suggestions?

Here’s some screen shots that show what I’m saying:
Blank Editor
Blank Editor Highlighted
Plugins Disabled