I have heard "Oh, Donna Clara" many times in the last eight years,
as the band plays this tune at the Austrian Club in Vancouver, B.C.

I sent for the music offered on eBay.  The version I received shows
Al Jolson taking up 60% of the cover page and the title of the tune
is very small at the top; all the above belittles the title.

I notice the description featured on YouTube says "Tango Milonga" as
was, I believe, made by the original publisher:

  http://www.youtube.com/watch?v=M7gs4Z_5XNo 

It really is not a milonga as such.  A milonga is a faster tempo and
rhythm with steps, and without pauses, as in a tango.

Milonga also means "a place (location) where dancing is and to take
place."  I was in Buenos Aires in 2010 and attended milongas.  I intend
to go again this coming winter.  I also intend to make an "O" roll
version of this tune, when time permits.

Steve Bentley - SB-"O" Rolls
Vancouver, British Columbia, Canada