KNS, it is for sure one of the 2 following issues:
1. You have a plugin conflict. Have you added any new plugins since publishing??
2. More than likely its an html problem. Have you added any extra code in by hand (especially unclosed DIV tags)? Did you put in any javascript or a Google or Facebook button – if so remove it? Did you add a WordPress caption to the picture and then modify it – if so remove it?
To fix it:
Take your page text as you see it in the wordpress editor, and then dump it into a plain text editor such as notepad. Save it!! Then in the wordpress post, select html, highlight and delete everything. Then switch the wordpress editor back to page view. Then repaste the notepad text back in.
You will lose all your formatting, and any pictures, but you may be able to save your post. You probably just modified the html of the post…
If that doesn't work, then email me the notepad html and I will take a look.
Cheers!