v.surf.spline: Bad input to routine SPLINE

[Kurt Gerber]

I'm runnig Grass 4.2 version 21 

I imported a ARC/INFO contours- vectorfile with m.in.e00 then I built the
topology with v.support -r.
When I tried then to build a Digital Elevation Model with v.surf.spline. It
first rasterized the lines (but only  7 steps, wich seems me little) an then in
"STEP 2 - Calculating splines for edges of contour map. The process stopped
with the error Message:  "ERROR: bad entry to routine SPLINE"
I didn't find a manual entry for v.surf.spline.  What does this error message
mean?