Guys, for the last 4 months or so, the analog stick of my PSP has been moving downside by itself. Like, when I'm playing Resistance, the character keeps moving backwards. When I'm playing WWE Smackdown vs Raw, the character keeps taunting. Of course, it's annoying me.

I've heard that if you keep moving the stick in circles when you're in the System Information screen in the XMB, it gets calibrated. But it doesn't work.

Is there any homebrew app that can help me calibrate my analog stick?
PSP Fat with TA-086 mobo, 5.50 GEN-B, by the way.

Thanks in advance. xD