There may be issues with the names of the models it seems. I messed around with the Units and saved a pmm with them. Later it couldn't find them and had to be told where they were (and it seemed to not like the name of the file when I clicked on them). The originals don't have this problem..
Nope, I only have this problem with a certain Meiko model. But I've only messed around with the Unit that has all the equipment. Just something about his file name that didn't stick.
But just pointing it out and all.