Behaviour of "Refresh on node update"

The "Refresh on node update" options works differently than its does in the D6 version of this module. I'm not certain exactly what is happening as there is no option yet in D7 to allow fields to be displayed when user is editing the node, but it seems that when unselected then fields are being cleared.

"Refresh on node update" selected = edit node and save then exif data is displayed when a node is viewed. (same functionality when a node is created)

"Refresh on node update" unselected = edit the same node again (one that had the fields populated) then the contents of those already populated fields is clobbered.

if a node is created when unselected - the exif is read and populated as expected - but then as above if that node is edited again it will be removed

I think this option should work as it did in D6 - if unselected then exif data is only read and populated on creation (this works), if selected then exif data is overwritten on every node save, and unselected makes no change to the fields on update. - but this only makes sense/can be tested when the module also offers the option of allowing the user the edit the contents of the fields when editing the node as they can in the D6 module visibility -> Show CCK Fields on Node-Update form)