Problem with Inventor's constraints

[oria297_rd]

Hello,

  I'm creating a plug-in with Autodesk Inventor 2014 and C# to automate the connection between spur gears and axis. Up to now everything has been smooth, but now I've stumbled with a very weird problem.

  In the attached assembly I've joined two gears together (g1-g2), each one joined with an axis(g1-a1,g2-a2), and each axis joined in another gear(a1-g3,a2-g4). As defined, the restrictions are completely valid, but if I rotate any gear the movement is not transmitted, as if it were blocked. However, if I disable a constraint, for example the connection between the last gears (g3-g4), it transmit the gears movement correctly.

  But I wonder:

     -Why the assembly doesn't move with the constraint activated? Inventor doesn't show any warning or error and theoretically it must work...
     -How can I access from C# any information about how Inventor internally handles this issue? Are there any internal errors or something similar?
     -Is there any way to configure Inventor, or query Inventor, to get information about this kind of "conflicts" between part movements/constraints?

  I would greatly appreciate any help to understand Inventor better!!

  best,

Oria297