Can't save levelmeter~ prototypes. Is this a bug?

Holland Hopson's icon

When I try to save levelmeter~ prototypes no file is created in the "object-prototypes" folder. I can successfully load the "M4L.black.maxproto" prototype. I can save and load prototypes for other objects such as number, flonum, umenu, etc. Anyone else encountered this?

Max 5.1.3 on Powerbook G4 PPC running 10.5.8