Unable to delete trash files

did you try using OnyX to force clear trash can?

 

With the possible corruption you can attempt to do a Repair Disk Permissions. You'll find this in the Disk Utility app. Select your hard drive from the left, then click the Verify Disk Permissions, and if it finds problems you can use the Repair Disk Permissions button.

Something else to try, go to Terminal, type: cd .Trash then type ls -ago and copy and paste the results here. It may reveal something about the files that we can use to help.

 

Have you tried Finder > Secure Empty Trash?

That has yet to fail me in Leopard and I've come across a few tough to delete file.

 

can you move the files from the trash to let us say, the desktop?

 

Or if all else fails you could give this ago

http://www.edenwaith.com/products/permanent eraser/

 

The trash widget can probably manage this.

 

I have the same file with the little null symbols and the two umlauts, I looked at it in terminal. It turns out that it is a file in the trash of my windows partition. So if you're like me and have a windows partition just try booting that up and emptying the recycling bin. In theory that will solve it, I'm just too impatient to boot XP to see if it actually works.