How many files are in the Trash?
Have you taken a look at Activity Monitor (Show All Processes) and seen the process called "locum" in there and using a lot of resources?
You could also use Terminal to empty the Trash and see if that is better: Force Empty Trash In OSX.
Btw, have you restarted your Mac yet and seen if that helps?
hi, when this happens to me i put trash back and then trash it from the finder for me it empties almost straight away. if not i reeboot and then it is gone.