When I copy files from my camera (connected via USB) to the SSD in my laptop a few files get copied and then the copy stalls. I'm not sure why, any ideas or things to investigate appreciated, or bug reports to go and look at.

I have read this answer - the camera (Canon 40D in case that matters) mounts fine using gvfs. I can see the photos in Nautilus, or in the terminal (in /run/user/username/gvfs/... ) and I can copy a few photos, but not many. Using the terminal or Nautilus the process hangs until the camera goes to sleep. Digikam fails to copy any at all, as does Rapid Photo Downloader. Shotwell did manage it in the end, but that is very much a work around for me.

I have disabled thumbnail generation by nautilus. Load average stays about 1 while this is happening, while CPU usage is half idle, half wait (and a little user/sys for other programs). None of the programs at the top of the cpu list in top are related to copying photos. There is not much in the logs - from /var/log/syslog

Dec  2 16:20:52 mishtop dbus[945]: [system] Activating service name='org.freedesktop.UDisks' (using servicehelper)
Dec  2 16:20:52 mishtop dbus[945]: [system] Successfully activated service 'org.freedesktop.UDisks'
Dec  2 16:21:24 mishtop kernel: [ 2297.180130] usb 2-2: new high-speed USB device number 4 using ehci_hcd
Dec  2 16:21:24 mishtop kernel: [ 2297.314272] usb 2-2: New USB device found, idVendor=04a9, idProduct=3146
Dec  2 16:21:24 mishtop kernel: [ 2297.314278] usb 2-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Dec  2 16:21:24 mishtop kernel: [ 2297.314283] usb 2-2: Product: Canon Digital Camera
Dec  2 16:21:24 mishtop kernel: [ 2297.314287] usb 2-2: Manufacturer: Canon Inc.
Dec  2 16:21:24 mishtop mtp-probe: checking bus 2, device 4: "/sys/devices/pci0000:00/0000:00:1d.7/usb2/2-2"
Dec  2 16:21:24 mishtop mtp-probe: bus: 2, device: 4 was not an MTP device

This problem has only started recently and I've had all the hardware for ages. I have also recently upgraded to 12.10, though I'm not sure if the problem started when I upgraded or after the upgrade. I also note this similar question but it is currently unanswered and I'm providing more detail