Why does my Mac want to permanately delete anything I put into the trash?

Everytime I go to throw something in the trash, I get a dialog box that says "Are you sure you want to permanately delete this file?" It's fine, cause usually I want to delete it permanately. But sometimes it is nice to go back in and recover files.

Any idea as to what happened? I never made a change...

Does this happen for all files? Say a file off the desktop vs a file from an external drive?

Or only in iTunes, iPhoto and not from Finder?

Or on a network share?

Network volumes and non-HFS (eg, Windows) volumes don't have a Trash that you can put things into.

All files. All files on external HDD, internal HDD, on desktop, on network, all, all, all. Very annoying.

Any ideas?

Assuming you have done so already, take a look at this Apple KB article.