Okay...
It must be perl... code works on an IBM RS6000
running AIX 4.3, perl version 5.005_03 .
I should have checked every system first for
incompatibilities before asking questions here
I'll just have to find a way around this, or get management
to upgrade Perl on all our platforms (can you spell 'Hell' ? :))
I'm sorry guys, thank you all so much for your help.