SkeletonData getTimestamp() issue

Hello, i’m making a connector within NuiTrack and the app of my work, and I found that the tdv::nuitrack::SkeletonData::getTimestamp() return allways the same value (¡!).
I found that issue developing our software and late I test it in your nuitrack_gl_sample onSkeletonUpdate callback with the same results.
Can you give some help with that? We need this value for our software because we are in the middle of the develop. Thanks!