I can't know for sure it's just a guess but I have a great book on Dens that really helps me TONS.
It's called Dendrobium and its Relatives
by, Bill Lavarack, Wayne Harris, and Geoff Stocker.
I found a pic in the book thats almost identical to your plant, but I don't have a scanner so I had to find a web photo to use of it. The web pic I found isn't as nice as the book picture
OB is such a great resource, filled with so many knowledgeable people! DJ you are truly a treasure!
I looked all through Jay's site, but was looking at only Dendrobiums, so I never would have found it, as he has it listed as diplocaulobium kirchianum!