Bizarre Battery Issues

Something odd is happening, and I can't figure out whether the issue is with my adapter or my battery. When I plug my laptop in, it starts to charge normally, but then it will spontaneously stop working, usually when the battery is mostly charged. But it only charges to 99%. It will still be attached to the adapter, but the icon shows how much battery life is left instead of the charged symbol, and the screen dims like when you unplug it. If I jiggle the adapter a bit where it connects to the laptop, it will usually start working again, but will stop again half a minute later. Then sometimes, it will switch quickly between working and not, making the screen flicker. And the light works very inconsistently. Sometimes it turns completely off when the laptop is actually charging, instead of brown. And sometimes when the icon shows that it's no longer connected, the green light will be on. I tried pulling the battery out and pushing the button for ten seconds, but it didn't help. School starts soon, and I'm getting a little worried that it will completely start working right when I need it! I don't hope I was able to explain this clearly.

You didn't give us much to go on. How old is the machine? How many charge recharge cycles are on the battery? Also include specs for your machine and which version of OS X you're using.

My mac's 2 years and a couple months old, cycle count 367, says my battery condition is good, using OS 10.5.8
Model Information:
Serial Number: SMP-ASMB016-3832-6b7
Manufacturer: SMP
Device name: ASMB016
Pack Lot Code: 0000
PCB Lot Code: 0000
Firmware Version: 0110
Hardware Revision: 0200
Cell Revision: 0102

I did an SMC reset, and option-command-P-R upon start up. Because I have to jiggle it to make it work should I assume that it's an adapter problem? I followed all the trouble shooting steps for the adapter, and I noticed that there's a little bit of space between the prongs and the outer area on the port. And how would I know if there's a problem with the logic board?

Does it act this way only when the battery is at or near 99%? If so, that is odd and I'm not sure what it could be, but if it acts this way all the time I have an idea. If it charges and stops charging at random moments, it could be your adapter. I just checked to make sure my theory would pan out and I think it might. The Mag-Safe adapter's prongs are spring-loaded. It could be that one or more of the prongs' springs are worn out and don't push it out firm enough to contact the areas on the adapter port on your laptop. Jiggling it may make them contact for a moment or even a while, but if the spring(s) are worn and weak, it will charge inconsistently like you said. Use a toothpick to gently poke at the prongs in the power adapter and see if they seem to pop back out firmly and completely. I'm not sure of any way to be sure this is the issue, but if it is, that's an easy fix. Buy a new power adapter. Good luck.