PB "goes to sleep" semi-randomly

Question

Ok, I know my battery doesn't hold a charge very well anymore and I've replaced my powersupply with a Macally one, but this is still very odd:
At work:
1) Battery says charged to 99% (=15 minutes, max)
2) Macally powersupply LED on, steady
3) PB never goes to sleep for no reason
At home:
1)Battery says 0% charged (or just plugged in)
2)PB goes to sleep for no apparent reason, none of the keyboard lights work (and only wakes up when I press the Power button)
3)After (but not before) such an episode, the Macally charger LED pulses on and off.
All other appliances plugged into that circuit/outlet work normally with no power surges, spikes, brown or blackouts.
Has anyone else had similar experiences? Any ideas on what may be causing this and how to stop it?
Thanks in advance
(12" 1.33Ghz, 768Mb RAM, OS 10.3.9)

Answer 1

With the later PowerBooks (the Aluminium ones) they upped the power-output of the Adapters: the one that came with my Aluminium PowerBook is rated at 65W and reported as such by System Profiler (in the 'power' section.)
Is it possible that your new adapter is a lower power rating? The models that came with earler PowerBooks (e.g. my original Titanium PowerBook G4) were only 45W. If I use this one - same connector - with my later machine, then the machine won't switch on until the battery has accumulated some charge (and won't switch on at all, if there's no battery inserted.)