Shotwell does not delete files it claims to...

I am using Shotwell to import and organize photos from my camera; these happen to be RW2 raw files from a Panasonic camera.

When I right-click on an image and choose "move to trash", then do "empty trash", I get choices:

This will remove the photo from your Shotwell library. Would you also like to move the file to your desktop trash? This action cannot be undone.
Cancel Only Remove Trash File.

If I choose Trash File, I get:
The photo or video cannot be moved to your desktop trash. Delete this file?
Keep Delete

I choose "Delete"... but it does not get removed from the filesystem.

The _shotwell.jpg proxy images do get removed, but not the RW2 files.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: shotwell 0.11.4-0ubuntu1 [modified: usr/share/glib-2.0/schemas/gschemas.compiled]
ProcVersionSignature: Ubuntu 3.0.0-13.22-generic 3.0.6
Uname: Linux 3.0.0-13-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Mon Nov 21 15:01:59 2011
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110802.1)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: shotwell
UpgradeStatus: Upgraded to oneiric on 2011-08-17 (95 days ago)