Thanks for your reply. Unfortunately, I still need more "specifics".
If I go to the "Maintenance" tab of the Gallery module, I can see the "Path" setting (on my local, working site) that shows something like:
/DNNv460/Portals/0/Gallery/375/
...and if I browse to this folder using [Windows/XP] Explorer, I can see that this is where my image files reside. However, if I go to DNN's File Manager, this folder does not even show up on the list. I just see "Host Root" with no sub-folders below it. I poked around there, but could not find a way for it to display (and therefore check permissions) to this folder.
I would appreciate any further details you could give me. Thank you.