Plugin hides Appearance/Menus panel

Probably related to the problem I also experienced and discussed in this thread:

but that's resolved (thanks again for that). However when I'm in wp-admin and go to Appearance --> Menus, I find that I have the left column (Custom links, Pages, Categories, etc.) but no menu builder on the right side. It's totally blank there. Disabling the plugin brings it back, so it's not as dire a problem as the original situation. This is a single-site install on WP 3.4.2 and I'm on v1.1.2 of the plugin. Thanks.