I also had this problem. There were things in the trash can that had root privileges. The root account doesn't have very good access to them. Anyways, I figured out the solution.

Open a terminal while in your regular account (not root account). go to the trash directory using this command:
That will take you to the correct folder in your terminal. Now you login as root by issuing the following command:
it will prompt you for the root password. Enter it and you will still be within your .Trash directory! Now all you need to do is delete the files using this command:
This will delete everything in the trash can including everything that had root privileges. To turn your terminal normal again without root privaleges, all you need to do is enter the command:
And you will be back to where you were before you switched to root.

I hope that helps !