There is a limit of 255 characters for the wall postings. When you type in more text than that you receive an error modal notification that you type in excess of 255 characters but if you click away the error, the text field is "muted"/deactivated and you cannot change or delete any characters anymore... you have to refresh the page and the text is gone. Second issue: When you type in excess of the limit the character counter stops at 0... In the profile post text field it goes from green to orange and then negative with a "minus" and red color. This would be a great addition to have a visual indicator that the user is doing something wrong. When I tried it, I didnt even realized I was typing too much text.