I had not used my g-tab in a few months and now if I charge it for 24 hours the battery indicator says the battery is only 1/2 way charged. I have always had to charge it overnight to get a full charge but now it only charges 1/2 way. Any suggestions? Also I have never been able to run the g-tab by plugging it into the wall. Plugging it into the wall is only good for charging it. I have to disconnect from the charger to use it. Is this normal?