Custom template ruined with update 1.4

We updated our site to 1.4 and now our custom template ceases to function correctly, we love all the new features but we need to work on a custom template that will support them in a test environment first. So we need to restore the old template for now, the way I understand it is that you have changed the wireframe template and this is why things are no longer working as they did before, would I be correct in saying that if I restore the old wireframe template that we should get functionality back?