Strange volume calculation


I am trying to calculate a volume of a solid, but it gives very strange results. The size of the shape is approximately 0.1x0.3x14 m with a rough volume estimate of 0.4 m^3. Rhino however calculates:
Calculating volume… Press Esc to cancel
Volume = 340.17 (+/- 0.021) cubic meters

Can anyone provide some clues what is going wrong here?

Kind regards, Sander
Version 5 SR14 64-bit
(5.14.522.8390, 5/22/2017)

Error_volume_calculation.3dm (467.2 KB)

Hi Sander - I see that V5 gets it wrong - V6 seems to get the right number, and if you Mesh the object in V5, the mesh volume is correct as far as I can see.


I need the volume in V5 so V6 is not really an option.
Meshing the object does not make a difference on my machine.


Here, Volume on the mesh, in V5, gets me .44644712 cu. mm. The exact number will depend on the mesh settings but should be in that neighborhood; the polysurface tells me its volume is 340.17 cu. mm. (the file is in mm)