Recently I had an extended battle with a Plone site that I upgraded to Plone 4.3. The site started life as a Plone 3 site and went through a series of upgrades and now runs on Plone 4.3.
Since removing pipbox fixed the problem, I didn't do any further analysis around the specifics of the conflict. I'm noting this in my blog in case someone else comes across a similar issue. Now I can get back to my little AngularJS side project :).