I think I can spot a difference ... but before you reformat your post with code-tags I'm not sure enough to tell. ;-)

UPDATE:

yeah better! =)

> perl -we 'print POSIX::cuserid'
Name "POSIX::cuserid" used only once: possible typo at -e line 1.
print() on unopened filehandle cuserid at -e line 1.
> perl -we 'use POSIX;print POSIX::cuserid'
lanx
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So what happens if you also use  POSIX?