I'm running into a problem very similar to the one described in this thread:
My application is utilizing a UIViewController for the implementation (actually, it is the libgdx implementation of the IOSUIViewController) and have the Google Ad Mob assembly from https://github.com/dalexsoto/AlexTouch.GoogleAdMobAds integrated. I set up AdMob in test mode. The ad appears and life is good. When I visit the test ad and then return, my screen quits rendering texture graphics. I know that OpenGL in the app is working to some extent -- the clear color that I have defined is being shown.... just no graphics. The screen is still responsive and the areas that have buttons defined are responding -- I can hear the sound effects that get played when they are touched.
I created an example OpenGL application and that works flawlessly. I can visit the test ad and return and the bouncing test block appears as expected.
Anybody have ideas why I'm seeing my textures disappear?