I have looked through the Galaxy Forge beginners guide (granted, not all 30 pages), and it doesn't appear to say anything about the issue I'm having. In fact, Google searching hasn't revealed the problem either. I assume that means that the problem is very simple, and I'm just dumb.
Anyways, I just started using Galaxy Forge, and I'm trying to save a test map to get a sense of scale, etc. However, when I save it to the Galaxy folder (yes, the one in the actual application folder, not the one under documents and settings), it does not show up anywhere. I changed the name of one map (Areolian Sector.galaxy to Areolian Sectors.galaxy), to see what would happen, and it disappeared from the list of Large Maps. This tells me that, somewhere, there must be some sort of Galaxy index that I need to add my map to. Other than that, I can't imagine what is wrong.
If anyone has a word of advice, I'd really appreciate it.
Edit: I am using Diplomacy 1.01.