Tuplets and partcombine

[Daniel Rosen]

This code:

%% Start

\version "2.16.1"

{ \partcombine
  { \times 2/3 { f'' f'' f'' } }
  { \times 2/3 { bes' bes' bes' } }
}

%% End

Gets me this error:

5:4: warning: No tuplet to end
  { 
    \times 2/3 { bes' bes' bes' } }

The file compiles fine, so I'm not sure what this is all about. Does anyone 
know? I see a couple discussions of this warning in the list archives, but 
nothing that points me toward a solution.

DR