@antwal - 3.8.1 will fix that. That is a PHP warning you should never see unless you have full debug mode enabled on the server. Regardless, I've patched that.
@mhirschberg - No idea why that would go away but there are a lot of behind-the-scenes changes to the menu tabs and how pages are built. It is the only way to allow new add-ons to be hooked into the base plugin properly. Maybe the 3.8.1 patch will fix that as there is something odd going on especially with MU installs. Try 3.8.1 and let me know what happens.
BTW, 3.8+ will be required for Enhanced Results / Enhanced Search / Tagalong versions coming out. Enhanced Results, for example, will let people easily change the under-the-map search results with a LOT more control than before. Without 3.8+ a lot of extended add-on features will not be available. A lot of "invisible" changes in 3.8 that make some extra "add-on magic" possible.