[thx1200]

Compusurf - That's what I was thinking, but I can't nail it down to a particular app. When I get this problem, I can close every app on the device and it never gets better. Also, I can listen to music (or watch videos or whatever) for hours and never get the problem. Then the next week, after two minutes it pops up. It's so freaking inconsistent and frustrating!

Talon - I will try that. If I could at least stop the problem after it starts (without a damn soft reset), then I would feel like I'm onto something.

EDIT: I forgot to mention, it's not like a gradual slow down over time. It's like an on/off switch. I check my phone and suddenly everything is crawling. No warning! Very sudden.