It's not exactly fair to be spreading rumours about Nokia chargers when you have no idea if it's true or not. A quick Google shows up nothing of substance. I'd be very doubtful about the accuracy of the claim.
Our hoover went on fire today ( smoke only ) ( in upstairs hallway ) and smoke alarm went off immediately ............We have not checked the smoke alarms in at least 2 years .......
Both claim that an unnamed charger caused a fire. No mention of Nokia.
If Noikia chargers had some defect causing fires, you'd see a lot more press than what you have posted. Nokia sells about 500 million phones per year, I think if there is a problem with their chargers you'd have really heard about it outside of the handful of links above.
I am onloy saying what the fire man told me it might save someone's life to pass it on.
Our microwave went on fire once and I was luckily in the room, I was about to go upstairs to check on my daughter but decided to wait. Caught fire in an instant and smoke alarm did go off, got an awful fright though