Please describe the problem:
gthumb does not create a directory .Trash-$USER when deleting images stored on a
mounted volume. As a result, gthumb cannot move these images to the trash.

Steps to reproduce:
1. Mount a disk (e.g. a USB stick) at /mnt/here/
2. Ensure you have rwx permissions for /mnt/here. Do 

      rm -r /mnt/here/.Trash-$USER

3. Open an image file stored on the mounted device at /mnt/here with gthumb in
browser mode. Select "Edit --> Move to wastebasket"


Actual results:
gthumb informs that it cannot move the image to the trash, and offers to delete
it immediately.

Expected results:
gthumb should silently create a directory /mnt/here/.Trash-$USER and move the
image to that trash directory. (This is what Nautilus does.)

Does this happen every time?
Yes (though I have only tested it on a USB stick formatted as FAT32)

Other information: