Neptune support answered my email in a few hours, and also suggested wiping memory.
So I saved the program XML to a file, wiped the outlet memory only, and then reprogrammed the outlets manually. I cut-and-pasted the programs from the XML file I had saved. Took about 5 minutes, so not too much of a hassle.
So if you see an outlet you don't recognize, don't delete it! Make sure you don't need it first.
In the future these outlets should be impossible to delete, or you should be able to recreate them easily. That would be a lot more user-friendly!