I have a Square "square" for reading credit cards (search for "Square" on the Market to see the app if you're not familiar with this). It works fine on my Samsung II S but refuses to read the same card on my EVO 3D. I suspect the reason is that when I plug in the reader to my audio port, the phone detects it as a headset and captures that port as an audio port even though I'm not in any application using audio at the moment (no phone, no music player, etc.). Does anyone know a way to either turn off this auto-detect feature or another way to get the "square" to work? The Square app sees that it's there, but I suspect when it tries to get access to the data, it's shut out for someone else is holding the resource open.