Help! booting problems

I've been having trouble booting my 1.25ghz Powerbook. Currently I have 10.3.3 and 10.2.7 on 2 partitions.

Originally the problem started when I removed the original Jaguar partition just to use Panther (changed the Start Up disk in Sys prefs 1st). Whenever I would shut down or restart the Mac there would be a startup bong as soon as I press the power button the dvd drive would click on and the hard drive would spin up but then the Mac would shut down again. After several times pressing the power button eventually it would boot but it was very erratic of when it wanted to boot.

Also I am unable to reset PRAM (not at all) or boot from the install DVD (not consistantly as well).

Eventually when I got it to boot from the dvd I re-installed Jaguar on the other partition but still have the same startup problems

The thing I noticed to be most different is the bong or chime immediately after pressing the power button.

Help Please!