Square button on PSP feels squishy

[erehwon]

I recently noticed that the square button on my PSP (2000 model) is squishy. It doesn't to spring backup as fast as the the other buttons. Does this mean that something needs to be replaced or cleaned? If so, how hard is it to clean open a PSP? I should note that it is modded and out of warranty, so I can't have Sony fix it.

[ErmangelnSeelen]

The square button on the US psp is actually different than the others. Yeah, it sucks. Get a Japanese one!