you could also, gasp, BUY a new battery - then see if it happens with the new battery - if yes, there's a problem with your pda or charging cable(s), if not, then at least you know the original battery was bad (and i'd send it in for replacement), and this way you'd also have 2 batteries = more power!
Although it doesn't sound like you have this problem, Lithium Ion Polymer batteries are very forgiving in some ways (you can charge for short periods of time without a memory effect), they also have a major downside - if it ever over-discharges, it will not hold a charge. period. ever. to overdischarge, you'd need to let it run all the way down, and then not charge it for weeks, i.e. the thing would have to really run itself down. once that happens, no charging in the world will help. then, at that point, you may want to take it apart to see what's inside, like i did! (you can read about that on
www.pdajunkie.net - trust me, it's not pretty
)