Swinging/Punchig/Breaking Blocks Bug

Dear Mojang and the Public,
I'm disappointed to inform you that I have found a new bug in minecraft
witch affects both game modes. This bug will not allow me to swing/punch/break blocks while I'm walking, even when I'm stationary there is approx a 3-4 second delay. Also to take into account that this bug has taken place only just after I upgraded my windows 8 to 8.1.
Please act on this quickly,
Yours Faithfully,
Mark Brown