We used to have a nice functionality which would split up 3D images in 2D images in order to save volumes as 2D .jpeg, .bmp or whatever format. This is especially nice for 3D images with 1 slice. Attached you will find a 3D RGB image with 1 slice which used to work.
I tried our last releases and figured out that this feature is gone for a while. It is not working in 2012-09, however, the checkout 388ed058 (one of the 2012-06 release) is working.