Error deleting file or folder

[splashpot]

I get this error message all the time when I'm trying to delete something.


And I am 100% sure that there is no program open using anything in this folder. I am certain of this because the folder is empty in this case. I know if I reboot, it will fix this and I will be able to delete it, but I was wondering if there is an easier way to fix this without rebooting.