VI only runs with probe

Hello,

I've run into a, for me, rather weird problem: a part of my VI should get data from a force sensor for further use. But this works for most of the time only if I put a probe in the error canal of this part (I've attached a picture of the exact location), without the probe, the SubVI crashes and returns a constant 0. Slowing the execution down with a timer didn't change anything.

This only happens if I run the VI with LabView 2012 under Windows 7, but works fine (without the probe) with LabView 2011 under Windows XP on an other (slower) PC.

Is this any kind of known problem?

Thanks for your help.