I'm trying to delete a file under OSX Lion, but can't. I get the following message:

The item XYZ.txt~ can’t be moved to the Trash because it can’t be deleted.

Here's what I've tried:

• select file and press COMMAND + DELETE (I get the message above.)
• renaming the file in finder (There is no option to rename the file.)
• sudo ls -a in a terminal (The file does not appear.)
• sudo rm XYZ.txt~ (I get "No such file or directory".)

How do I remove this file?

EDIT

The file went away after restarting. My guess is that it was a glitch in finder.