In your second post I think you may be missing a closing div.
It could be related to this in your code…
<div class="saving" />
<div class="saving">
An easy way to check is to remove that post for a moment – just copy the code to a text editor – and see if that brings your sidebar back into place.
If so, you can then find the culprit easily. if not, try the first post in the same mamnner.