My first round of golf, so be gentle... I took a slightly different route to get to the same solution:

use strict;
my @p = (1,1,1,1,1,1,1,1,2,1,1,1);
print perl(),"\n";

sub perl{sub w{my$h=int(($_[1]-$_[0])/2+$_[0]);$"='+';my$o=eval"@p[$_[
+0]..$h]";
my$t=eval"@p[$h+1..$_[1]]";$o<=>$t?(($o<=>$t)==1?($_[0],$h):($h+1,$_[1
+])):undef;}
my@r=w(w(0,11));my$v=$p[$r[0]]<=>$p[$r[0]+1];$v?($v==1?$r[0]:$r[0]+1):
+$r[1];}
[download]

I count this at 237 characters. Hopefully I haven't violated any of the rules...

--jwest

-><- -><- -><- -><- -><-
All things are Perfect
    To every last Flaw
    And bound in accord
         With Eris's Law
 - HBT; The Book of Advice, 1:7