Moog Etherwave Standard. Power supply

So I have been having an issue with my power supply lately. It seems to fall out occasionally with the slightest bump. I look at the connector (the part that plugs into the theremin) and I notice only three little prongs. Is this correct? Has anyone else had a issue with the power supply falling out?

The three pins are correct. For reasons I cannot imagine Moog chose to use a three pin DIN connector for the power supply. I have not had any problems with mine yet, but I treat it with inordinate care as it is an obvious weakness.

I believe that the power supply has a positive
and negative voltage and a return which requires
at least three pins.

(* jcl *)

P.S. I should add that the DIN connector is a common
connector used for multi-output supplies.

I've seen plenty of items that use Power DIN (http://en.wikipedia.org/wiki/DC_connector#Snap_and_Lock_DC_Power_Connectors), but not Audio DIN.

(Fortunately none of my audio equipment has Audio DIN sockets, so I have not been able to destroy them by plugging the power supply into an audio-in.)

DIN connectors are extremely uncommon in commercially manufactured products in the US. Mostly they were used in 80's era home computing products of poor quality. Consequently every time I have to look at that DIN connector on the Etherwave and its supply, I shudder a little, knowing that every other DIN connector I've ever had has gone horribly wrong sooner or later.

So I have been having an issue with my power supply lately.  It seems to fall out occasionally with the slightest bump.  I look at the connector (the part that plugs into the theremin) and I notice only three little prongs.  Is this correct?  Has anyone else had a issue with the power supply falling out?

Just purchased a Moog Grandmother, identical issue. The plug-in portion of the connection is too small, and it gets noisy when moved at all.