That particular transaction is 10.9kB larger than the default maximum allowed transaction size which is 100,000 bytes.
There must be a lot of inputs included.

I guess you're sending all of your wallet's balance....
But anyways, try to remove some of the low-value inputs by displaying the Coins tab (View->Show Coins),
then freeze (right_click->freeze) the one's with very low amount to exclude them to your transaction.