Can't delete .plist files from Trash
When you have problems to empty the trash, rm -rf ~/.Trash/* in the terminal does the job for you. 

Edit :

You have to keep in mind that there might be multiple .Trash directories. 
For example on a USB stick or a external Drive, OSX will create another .Trash at the root of the drive. So you might need to use  rm -rf /Volumes/DriveName/.Trash.*