Hi Kris,
To be sure, are both of those CentOS systems running the
exact same version of AFNI, the exact same set of binaries?
Can you report "afni -ver" on each system?
I ask because there was a change made to 3dDespike around
that time which would indeed lead to slightly different results.
The program was made to be much faster. Either result should
be considered "correct", but they are indeed a little different.
- rick