Batteries used in a range of Nokia handsets, from the 1100 to the latest E60, are at risk of overheating during charging. Of 300 million BL-5C batteries manufactured by Matsushita Battery Industrial Co. for Nokia last year, 46 million belong to the dodgy batch.
One hundred incidents have already been reported, but none have resulted in explosions, fire, or even a burnt finger. However, Nokia has said if your phone has a BL-5C battery you should probably keep an eye on it when charging.
Or, visit Nokia's website and check your battery's serial number against a list of the dodgy ones. If it appears on the list, Nokia will provide a replacement free of charge. Which is nice.
Though the risk seems minimal, and Nokia is certainly playing down any danger, it's probably worth checking. ®