hey, I'm having trouble with an external keyboard I purchased for my Nexus 7. it keeps typing in multiple characters even though I press the character once. for example pressing M once will give me MMMMMMMMMMMM. it happened once with a logitech bluetooth keyboard I bought, and thought it might be deffective hardware, so I returned it, but when I got an Anker bluetooth keyboard it did the same thing. it's becoming a big issue while I type, and it's pissing me off. can anybody help?