Sony Ericsson's BST-33 Li-Polymer batteries swelling into a lawsuit?

We've seen plenty of swollen and exploding batteries 'round here, but this is the first Li-Polymer battery (a technology generally assumed to be more stable and less prone to swelling and fire than Li-Ion) that we can recall ballooning into such a possible danger. Reader Christian sent us these pics of what's normally a 4-mm thick battery (pictured right) inside his W880i handset now swollen to a full 7-mm. The BST-33 sits at the heart of a long list of SE phones, a list we've included after the break along with one more picture. Do let us know if you're seeing similar issues.

List of compatible Sony Ericsson phones: C702, G502, K530i, K550im, K800i, K810i, M600i, P1i, P990i, W300i, W302, W595, W610i, W660i, W705, W850i, W880i, W950i, W960i, Z320i, Z530i, Z610i, Z750i