Will not Publish or Edit.

I wrote my first post and when I hit the Publish button the screen went white… I hit refresh a couple of times which did nothing. I then hit the Back button and it returned me to the New Post screen which was blank. Fortunately when I went to the Manage Posts it had been saved. When I hit the Edit button, it brings me to the same white screen as when i tried to Publish.

I have tried to do new posts and the same thing happens. Any advice?