Nokia has identified that in very rare cases the affected batteries could potentially experience over heating initiated by a short circuit while charging, causing the battery to dislodge. Nokia is working closely with relevant local authorities to investigate this situation.
While the occurence in the BL-5C batteries produced by Matsushita in the time-period specified is very rare, for consumers wishing to do so, Nokia and Matsushita offer to replace for free any BL-5C battery subject to this product advisory.
Check the full communicate at http://www.nokia.com/batteryreplacement/en/
You might get a new battery for free!
Hope it helps