I thought I'd add to this post because I was having a lot of trouble with gtkam. It seems it didn't like my laptop (very old hardware now) or OS (Linux Mint 14 "Nadia") or something. Anyway, the connection kept "dropping" and I would get an error message saying it couldn't access the Toppy. I needed a cast-iron way of getting the files to download.

So here's how I fixed it, which I thought I'd share in case anyone else was in the same position as me...(ideally you'll need to be familiar with the linux terminal, but if you're not try copying and pasting the commands in and see what happens. If you want to know more about the commands type "gphoto2" into a browser and look for chapter 2 of its manual, or type the commands into a browser and see what they bring up).

nb the use of "Sudo" seemed to over-ride the objections I was getting about the Toppy being "in use" or "unavailable". if you don't know what Sudo is you should probably stop here and do some research before you go any further.

First, install gphoto2 and any libraries it needs. You can do this from Synaptic or in a terminal ("sudo apt-get install gphoto2")

Connect the Toppy, then unmount it in the file manager (as described in the post above).

Start a terminal and change the active (current) directory to the location where you want to store the downloaded files. In my case this was the Desktop, so "cd Desktop"

Check the Topfield is visible "sudo gphoto2 --auto-detect" (the long dash before "auto-detect" is a double dash, ie "-" then another "-" straight after it. Similarly for "--list-files" and "--get-file", below)

Get a list of all the files available for download "sudo gphoto2 --list-files"

Scoll up through the list and find the number of the file you want to download e.g. #133. Ignore the "#", so in my example just "133"

Download the file "sudo gphoto2 --get-file 133" and the file should download to the current directory (Desktop, in my case)

There are ways to download more than one file at a time, which are listed in the gphoto MAN pages, but I'm happy with one at a time.