I am having the same problem. Have previously entered keywords, title and description on a few pages, but now I can't edit them. Whatever changes I make it does not save them.
I don't want to disable my theme as it removes all the widgets from the position their in, and I have to rebuild them all. Rubbish I know, but that's life.
Do you have any other ideas how this can be edited? I'd be happy to change the data directly in the database through PHP MyAdmin if you point me in the right direction of where to look?