All new posts take me to a blank page, does not post.

We have several writers for our blog and starting about Saturday night, whenever we click “Publish” we are taken to a blank white page – no wordpress anything on it. We then have to use the ‘back’ button and are unable to publish anything new. The same happens when we try to edit existing posts.

We tried to get around this by upgrading to wp 2.3.3 last night, but everything is still broken.

Help!