I was wondering why Waze goes into black screen after clicking the report button along with Flipboard, after coming back from recently opened apps. I found out that these apps will go into this state on mostly de-odexed ROMs, I did however tried on my stock odexed samsung ROM, xxltc recently released somewhere around January I think.
What came to my surprise was that Waze didn't go into black screen. Rather, it just performs normally. If you're on the de-odexed ROM, chances to get the black screen is quite high. To get the normal behavior, you need to relaunch the app again.