Yes, I experienced this as well :)
The problem occurred because the HTML of that particular post to be moderated contained a <FORM> tag. This messed up the form that contained the buttons for moderation. The solution (now implemented) is to beef up function qa_sanitize_html(...) in qa-base.php so that:
'elements' => '*+embed+object',
... becomes ...
'elements' => '*+embed+object-form',
I don't think there is any good reason for a user to have an HTML form in their post. The fix will be in Q2A 1.6.3.