I have been having problems for some time trying to use F-spot with a Nikon D300s camera on various versions of Ubuntu (8.10, 9.04, 9.10, 10.04) and my frustrated rants are covered here:
https://bugs.launchpad.net/ubuntu/+source/f-spot/+bug/191316
https://bugs.launchpad.net/ubuntu/+source/f-spot/+bug/74279
However, the fault is not specific to F-spot and appears in gphoto2 as well:
https://sourceforge.net/tracker/?func=detail&atid=108874&aid=3004614&group_id=8874
Where I finally got somewhere as the problem appears to be due to gvfs-gphoto2-volume-monitor grabbing the camera and then the following application (typically F-spot) can't access the camera while it is already open. Now I found this comment:
http://mail.gnome.org/archives/gvfs-list/2009-May/msg00001.html
The implication is that applications should be going though gvfs-gphoto2-volume-monitor, rather than doing to libgphoto2, for camera access in modern gnome distributions for various reasons. OK, I can't imagine much *need* to share a camera on most desktop PCs, but the principle is sound (open once and then let others go via the common interface).
As F-spot is one of those applications that is not working properly due to this, what can be done? Is it easy to change to use the gvfs-gphoto2-volume-monitor back-end for distributions like Ubuntu?
I worry that simply and permanently killing gvfs-gphoto2-volume-monitor by "chmod a-x" is going to upset something else, if not now, in the near future.