i installed ubuntu 12.04 and it was working perfectly, but from yesterday i have a problem, when i am pressing left ctrl key it doesn't responding but when i pressed Fn key it works as a ctrl key and loses its own functioning,same with the delete(del) key it works as a pause/break key and pause/break key is working as a delete key.numlock key is working as a print screen key, after that i updated my os but the problem is still happening. pls tell me what to do.