2;0 juerd@ouranos:~$ perl -l
while ("this_is_broken_" =~ /(.*?)_/gs) {
  print "($1) ";
}
(this)
2;0 juerd@ouranos:~$ perl -l
while ("this_is_broken_" =~ /(.*?)_/g) {
  print "($1) ";
}
(this)
(is)
(broken)
2;0 juerd@ouranos:~$ perl -v

This is perl, v5.6.1 built for i386-linux
=cut :)
[download]

This is on Debian Sid, the current perl package (5.6.1-6

2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$
[download]