having trouble deleting files

hi. i have several files that will not delete. they are in the trash, but when i go to empty trash, the dialogue box opens and sits doing nothing. the only way to cancel it is to force quit the finder but when i do that, the finder disappears - no title bar, no response when i click it in the dock - and there is nothing when i cmd-tab. i end up restarting computer and the finder works again and the files are still in the trash. any ideas?