As BUU already suggested, this is probably because /usr/local/bin/perl does not exist. What is curious though, is that your code says #!/usr/bin/perl not #!/usr/local/bin/perl ...? Maybe that was just a typo/cut'n'paste error on your part. If not then I'm not sure what's going on.

One other thing that could cause this error is some spurious CR/LF characters on the end of the #! line. For example if you developed the Perl script on a Windows machine then FTPed it to your Unix box, but forgot to transfer it in ASCII mode, then the #! line will have an ASCII-13 at the end which confuses most Unix shells. Some Unix editors (I think EMACS does this) will show this up as: #!/usr/bin/perl^M . Not sure if that's the problem in this case but it's something to look out for.