Node numbers different in mesh and post processing

Hi,

I am carrying out fea of a pressure vessel and I need to find out the stresses on the nodes.

This is what I am doing
1. Clip the model where I need to find nodes and using "mesh info" and clicking on real vent node I find out node numbers
2. In resu file where I have exported all results, I find out the node number and see von mises and displacements

All good till now, but recently I found out that I can select a node/element in post processing directly in Salome and find out stresses. But the problem is that even if I pick the exact same node in the same location, the node number shown in post processing is 1 less than what is shown in mesh module.

Is there a bug somewhere or does post processing work on [0] base and meshe module work on [1] base?

Thanks
Dharmit