dcraw: Cannot decode file (JPEG from Nikon COOLPIX)

Binary package hint: dcraw

I want to open a JPEG file (a photo taken by Nikon COOLPIX S5100 camera) in GIMP 2.6.11 on ubuntu 11.04. (I do it by issuing the command in GNOME terminal). I can see a warning and also other message. Not everything is bad because the image is displayed in the GIMP window but there is the seriously looking dcraw-related message. See below.

gimp DSCN0020.jpg

(gimp:3111): GLib-WARNING **: /build/buildd/glib2.0-2.28.6/./glib/goption.c:2132: ignoring no-arg, optional-arg or filename flags (8) on option of type 0
dcraw -i '/home/konopka/fotky_cvicne/Coolpix/DSCN0020.jpg'
Cannot decode file /home/konopka/fotky_cvicne/Coolpix/DSCN0020.jpg

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: dcraw 8.99-1
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
Architecture: i386
Date: Sun May 8 22:32:19 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Beta i386 (20110413)
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_GB.utf8
 LC_MESSAGES=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: dcraw
UpgradeStatus: No upgrade log present (probably fresh install)