Edit buttons in ‘Publish’ bar not working

When I am posting on my blog, and go to click the ‘edit’ buttons in the Publish bar to
a) ‘stick to the front page’ or
b) edit the time for publishing’

… i click ‘edit’ to expand those options and nothing happens. It says ‘Error on page’ along the bottom of the page and I just get moved down the page slightly.

It’s a real problem, as all my posts are disappearing into the archive somewhere and I cannot time posts to publish later.

Any ideas? It’s driving me mad!

Thanks everyone – Rachel