Thank you, Daniel.
I will try pigz and see if things get better.
I am intrigued by the delay suggestion and it got me wondering whether it is possible to trap for this error within AFNI's I/O and have the operation sleep for a bit before trying again, but only when needed. I suspect this problem occurs more often when using network file systems and when running parallel processes with file I/O. Setting a delay at the script level would slow everything down to fix a few occurrences.
I don't mean to be piling on the team's plate, but some guidance on how to best fix this might help the next intrepid developer to implement it.
Cheers,
Z