trouble charging tablets

And it gets even better. If you don't care for your battery properly, you won't even get the mythical 300 charges out of it.
Five tips for extending lithium-ion battery life | TechRepublic
I suspect the kids in the original post of this thread were running the battery completely out before charging, not knowing that's a bad thing for Lithium-Ion batteries.

You're probably right-I didn't know that either so that's probably what happened to mine too. I never purposely let it run completely out but a few times it did because of that stupid bug where it refuses to stay asleep. I'd set it down, fully charged and get distracted and come back the next day to see the battery had gotten completely drained. I'm very disappointed in Coby right now. I have a $200 paperweight. Now we know why they only have a 90 day warranty!