more Tuplets...

[Marcos Press]

Hi list!
I always have some problems with the tuplets, but generaly I end up findig a solusion by my own. Today is not the day :)

The problem is more with the spanner but I'm not sure the tuplet is configured correcly.
Here, all seams ok.
Compile with no error and perfect graphic with one spanner over the complete tuplet.

%%%%%
\version "2.15.40"

\relative d'' {
  \clef G
  \time 6/8
  \key a \major
  a2.
  % \set tupletSpannerDuration = #(ly:make-moment 1 3)
  \times 6/4 { e16[ fis g gis] a[ ais b b] }
  a2. | a2. | a2. | a2. | a2.
  \bar "|."
}
%%%%%

Uncommenting the \set line produce extra spanner lines over the nexts bars. And adding again the tuplet, adds nested spanners over the nexts bars.
I'm pretty sure the tuplet numbers are wrong and the SpannerDuration moments are wrong too :)

Can anyone help me with the complex simplicity of tuplets?
Thanks!!!