Disappearing/deleted .pls files

I am making application that is using .pls files to read shoutcasts' adresses from them. At one moment I noticed, that sometimes .pls file I was reading data from is disappearing after I have used it. After lots of testing, I noticed, that if I rename file to .txt, it won't get deleted. A little more testing, a voila - sometimes, if I read data from one .pls file (pathname provided in String), ALL .pls files on sdcard get deleted! And my doing anything with any of them - they just all get deleted. I am using HTC Desire Z, Android 2.3.3, not rooted, and I don't remember installing any applications that could be deleting files, especially without my knowledge. Any ideas? I can provide you with the app code I am using, but I don't really think it is connected in anyway to this problem.