[Gmsh] Using IGES points

[Henk]

Dear all,

a peculiar behavior with an IGES file. The script with only two 
lines:

Merge "igesfile.igs";
l1 = newl; Line(l1) = {42, 67};

Results in a crash. In ~/.gmsh-errors it says:

Info    : -------------------------------------------------------
Info    : Gmsh version   : 2.4.2
Info    : Build OS       : Linux
Info    : Build options  : ...
Info    : Build date     : 20090921
...
Info    : Reading 'test.geo'
Info    : Reading 'igesfile.igs'
Info    : Healing geometry (tolerance=1e-06)
Info    : - fixing small edges
Info    : - fixing spot and strip faces
Info    : - sewing faces
Info    : Read 'igesfile.igs'
Error   : Unknown control point 42 in Curve 1
Error   : Unknown control point 67 in Curve 1
Fatal   : Wrong list index (read)
Info    : Writing '/home/hk/.gmsh-errors'

Apart from the default settings only the geometry option "Sew faces 
in OpenCascade models¨ was set (in order to remove duplicate points 
and lines). The Points 42 and 67 are there and visible...

Any hints how to proceed please?
Thanks!
Henk