A user on the NeoWin forums has posted a story and pictures of his PowerBook G4 AC adapter that burst into flames:

I was in the kitchen and the fire alarm went off in my room. I went back to my room and found the power brick for my Powerbook G4 sparking and smoking and it had lit a notebook on my desk on fire. Is this normal? Safe? I mean normal wear and tear is one thing but the brick looked to be in perfect shape. It wasnt frayed or discolored or anything that would have hinted it was a danger to me. Then all the sudden boom its on fire I mean thats not right. If i take the brick to the apple store will they give me a new one for free? I’m not interested in suing or something crazy. Though i am crazy freaked out, what if i hadn’t been home? Or was sleeping? Even out of warranty they aren’t suppose to start fires are they? Please I need advice.

Although flare-ups like this are a rare occurrence, the frightening potential for greater damage is very real and dangerous. We have reported on similar incidentsin the past. While there is no clear culprit, most feel it is the gradual degradation of the insulating rubber that can lead to these sparking meltdowns.