Figured it out and also corroborated it by finding a thread (that I can't find now, unfortunately). Anyway, it's the SD notification sound. If your SD notification noise is set to a custom noise, it will cause this problem. The solution is to either disable to SD notification noise, or change it to a stock tone. I personally had it set to a custom .mp3 file that I had, but I switched it back to the "Droid" tone, and now I get no problems.
Hope this helps.