After upgrade to 3.2.12, any installed, gantry-based template has the same problem. Under the Administrator Template Manager, (Styles tab) the link for each gantry-based template points to something similar to this:
The short term solution is to select the checkbox and click on the edit icon, but would like to see this properly addressed. On the Joomla.org forums, one person claimed the problem went away when he installed a new Gantry template, but I just installed the stand-alone for Entropy with no such luck.
I was able to duplicate the same problem on 8 different Joomla installations, all running Joomla 1.7.2. From all appearances, everything else on the front and back-end seem to be working properly.
In your back end Template Manager screen click the icon labelled OPTIONS. A popup window should open and you'll see a tab Template Manager Options then change Preview Module Positions to Disabled.