This happens to me all the time... My favorite music app for Android is Poweramp, and I love the popup texts that MIUI has. But for some odd reason, when I am listening to music and I get a text message, my phone freezes. I can click the text box that pops up, and it takes me to Messages, but I cannot click anything with the touch screen. If I wait a bit, I can use my trackpad a little, but even that lags. The physical buttons work occasionally, but it is as if the combination of Poweramp and MIUI Popup texts just throttles the CPU and it just can't handle it. And the solution I have to resort to is pulling out my battery and putting it back in. I have not tried with other music players. But I have tried taking the popups off and it works fine. Any thoughts?