Hello Bruno.
I tried both the binary and source versions of visit 2.6.3 and they both show the same problem. I also tried the 2.6.0 binary version and it shows the same problem too. Any idea of what's going on?
I would try and see if the difference is due to cell vs. node plotting (ie the Centering option of a pseudocolorplot which can be natural, nodal or zonal).
Yours, Roland