hot power adaptor (square white ones) for TiBook

[Stephen Eglen]

Can anyone shed light on the following issue?  

I have a G4 titanium powerbook (1 Ghz), and a couple of weeks ago the
[white square] power adaptor broke down -- the light (indicating
charging/charge) at the end of the adaptor stopped working, and the
adaptor was very hot and smelt burnt.

I got a replacement from Apple under apple care, but now I've noticed
the replacement is running hot too when the machine is on and
charging, although it still works currently.  Is there likely to be
anything wrong with my laptop?  Apple didn't seemed to know much about
this, and suggested I send it in for an engineer to look at, but I'd
rather not lose it for a few days just yet.

Thanks,
Stephen