GUI created in GUIDE has become non-functional

I have a GUI I created using GUIDE that I continue to expand with more buttons and menus, etc. But since upgrading to R2013a, I've run into two major issues:

First, adding objects to the .fig file was not generating the accompanying callback/create function components in the .m file upon saving, as it had been (i.e. I could add a new object but I couldn't use it). The only solution that I have found is re-saving the GUI under a different name, which generates a fresh .m file.

Second, all or most of my radio buttons and push buttons have stopped executing their callback functions, rendering the whole GUI useless. The tags all seem to match up, so I'm not sure where to start in trying to fix them. It's like the objects and their callbacks have become disconnected somehow.

These seem to be R2013a bugs. Does anyone have a fix for them?