Editing Issue.

I'm having problem "edit" my PM posts, after i posted my reply in PM then i try to edit it to correct some typo mistakes. I clicked on "edit", got the page but the page layout seem corrupted, when i point my cursor over the message and click, i get a "no entry" sign, can't highlight, can't correct anything and there's no cancel button as the page is corrupted and i can't find the save or cancel button, even after refreshing the page several time...