Sigma 17-50 f/2.8 - OS/VR indication on exif (CaptureNX2)

I recently bought a Sigma 17-50 f/2.8 and use it with my D7000.

When viewing the image properties in Capture NX2 for all images captured with this lens, VR is always indicated as "On". This happens for all images I captured with this lens, even for those where the OS button was switched off.

I don't know if this is just a comunication "bug" between the lens and the camera, or if my lens OS on/off button is not working properly (and I am not being able to turn OS off...)

• Did anyone else experience the same issue?

• Is there a simple way of checking if the OS is on or off apart from looking at the image exif?

Thanks for any input you can give me on this.

Regards,
João