unable to import photos (gthumb/shotwell/file system)

[kex]

I am unable to import photos from my canon camera.

Shotwell just crashes.

Gthumb gives the following error:

DBus error org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

The whole computer becomes unresponsive for about a minute, and the led in the camera flashes.

Trying to look at .gvfs with ls: it is possible to cd to the DCIM directory, but "ls" makes again the system unresponsive, and after a minute or two, there is an "I/O error"

lsusb tells:
Bus 009 Device 009: ID 04a9:3101 Canon, Inc.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: gthumb 3:2.14.3-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-26.41-generic 3.2.19
Uname: Linux 3.2.0-26-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu8
Architecture: amd64
Date: Sat Jun 30 09:56:43 2012
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
SourcePackage: gthumb
UpgradeStatus: Upgraded to precise on 2012-04-25 (65 days ago)

[kex (kex-iki)]

a note; with a different Canon camera:

lsusb:
Bus 009 Device 002: ID 04a9:314f Canon, Inc. Powershot SD1000

it works fine. The problem seems to be with the Canon EOS camera driver or some package controlling it?

[kex (kex-iki)]

Additional note; I tried the Printing/PTP mode in the camera settings instead of PC-connection; with PTP mode the photos are transferred OK; the problem only concerns the PC-connection mode.