Nothing to connect extender to - warning: Why?

[Yotam Medini]

(Version 1.3.119).

It seems using extenders (__) gives a strange warning,
even though they do seem to work. 
For example trying the released tutoial example 'flowing.ly' gives:
{ ================================================================
GNU LilyPond 1.3.119.
Now processing: `flowing.ly'
Parsing...
Interpreting music...Failed typecheck for `noAutoBeaming', value `"1"' must be 
of type `boolean'
warning: Can't find property type-check for `automaticMelismas'.  Perhaps you 
made a typing error?

MIDI output to flowing.midi...
Track ... 

Interpreting music...warning: Can't find property type-check for 
`invisible-staff'.  Perhaps you made a typing error?

flowing.ly:21:9: warning: Junking request: `Rest_req':
        c
         2:3- f:3-.7 d:min es4 c8:min r8
Failed typecheck for `noAutoBeaming', value `"1"' must be of type `boolean'
warning: Can't find property type-check for `automaticMelismas'.  Perhaps you 
made a typing error?

flowing.ly:15:32: warning: Nothing to connect extender to on the left.  
Ignoring extender request.:
        The ri -- ver is flo- __
                                 wing, flo -- wing and gro -- wing, the

flowing.ly:15:32: warning: Nothing to connect extender to on the left.  
Ignoring extender request.:
        The ri -- ver is flo- __
                                 wing, flo -- wing and gro -- wing, the

flowing.ly:22:9: warning: Junking request: `Rest_req':
        c
         2:min f:min7 g:7^3.5 c:min }
[7]
Preprocessing elements... 
Calculating column positions... [3][6][7]
paper output to flowing.tex...
} ================================================================

This  'warning: Nothing to connect extender to on the left'
remains even having the fix:

 celini:211> diff flowing.ly flow.ly
 31,32c31,34
 <              {       \property Staff.noAutoBeaming = "1"
 <              \property Staff.automaticMelismas = "1"
 ---
 >              {       % \property Staff.noAutoBeaming = "1"
 >                      \property Staff.noAutoBeaming = ##t
 >              % \property Staff.automaticMelismas = "1"
 >              \property Staff.automaticMelismata = ##t

Any hints? 
Please copy me (address@hidden) as I am not following
these lists carefully.

thanks -- yotam