You made the same mistake I originally did whilst visually checking my own palindrome: flipping the paired punctuation, that is parenthesis, braces, brackets. See blokhead's initial reply to my OP.

My checker scripts makes it show up a bit better.

jbm@Foucault:~/Code/perl
$ debug=1 ./check_palindrome.pl javafan2.pl 
text = #!/usr/bin/perlBEGIN{closeSTDERR;print"JustanotherPerlhacker"}{
+"rekcahlrePrehtonatsuJ"tnirp;RREDTSclose}NIGEBlrep/nib/rsu/!#
length = 124
middle = 62
half1 = #!/usr/bin/perlBEGIN{closeSTDERR;print"JustanotherPerlhacker"}
half2 = {"rekcahlrePrehtonatsuJ"tnirp;RREDTSclose}NIGEBlrep/nib/rsu/!#
flip  = #!/usr/bin/perlBEGIN}esolcSTDERR;print"JustanotherPerlhacker"{
javafan2.pl: NOT a palindrome.
[download]

Your others check out fine.

jbm@Foucault:~/Code/perl
$ ./check_palindrome.pl javafan*
javafan.pl: Palindome OK.
javafan2.pl: NOT a palindrome.
javafan3.pl: Palindome OK.
javafan4.pl: Palindome OK.
[download]