Admob prevents TextView UI updates with a CountDownTimer in Android?

Question

I'm adding admob ads to my app that has a CountDownTimer that changes a time countdown display in its onTick() callback function. The time display uses a TextView and is changed via .setText(). Everything works fine until I add the admob code. Seems that the ads break the TextView redraws when running. When I stop the CountDownTimer and update the TextView, the redraw happens. I'm not certain why this is happening, and since CountDownTimer is implemented using os.Handler, I can't think of a better way to do this. Calling TextView.invalidate doesn't work either.

Any ideas?