Resolution

This problem was caused by these files that are hardlinks:

/usr/bin/perl
/usr/bin/perl5.8.5
/usr/bin/suidperl

but /usr/bin/suidperl must be a hardlink to /usr/bin/sperl5.8.5

You should delete /usr/bin/suidperl and create new /usr/bin/suidperl:

# ln /usr/bin/sperl5.8.5 /usr/bin/suidperl
# chmod 4755 /usr/bin/suidperl

and set the right permissions to /usr/bin/perl:

# chmod 755 /usr/bin/perl