Isn't this just a case of setting your path to perl correct?So instead of call 'perl my-script.ipl' do '{iw-home}/perl/bin/perl my-script.ipl'?(This should be considered a good-practice any way)
Looks like it is still loading the perl modules from the 5.6 directory instead of the perl 5.8 directory. You should change it to point to the 5.8 modules library instead.
Could you please provide some input as how it can be done? As i have already tried to change the ENV variables on the server itself.