After the Bionic ICS upgrade the button on my wired headset is not recognized if the screen is dark.
I am using the Headset Button Controller app. Before the upgrade it worked with out a flaw. Now, if the screen is dark the button is ignored. To be clear, the screen does not have to be in the Locked state, just dark for the button to be ignored.
I reported this to the DEV of the Headset Button Controller app, he replied he is recieving this complaint from users of Motorola devices runnig ICS. And it is a Motorola problem and cannot be fixed by app developers.
Even with the app disabled, the stock music player has the same problem. As long a the screen is active the button action works - when the screen is dark the button is ignored.
This makes headset button contol useless if you have to take the phone out of your pocket and turn it on to pause or play your music.
Posted this on the motorola users forum also, If I hear from them I will update this post.