ipad 2 charges only when off

I had problems with charging my ipad 2 since yesterday.

I am using the apple provided charging adapter/cable and charging using the electrical point.

But I am able to charge only when the ipad2 is switched off.

Questions

1.The charging doesn't happen if the ipad2 is ON (through the electrical point).

2.It takes a very long time to charge from 0->100% when using charging from a electrical point

Has anyone faced similar problem before ? Any solution ?

Please note that i am not using the laptop/computer to charge.

thanks.