$r->subprocess_env('REQUEST_URI') returns undef ?

From:
http://perl.apache.org/docs/2.0/api/Apache2/RequestRec.html#C_subprocess_env_

subprocess_env

Get/set the Apache subprocess_env table, or optionally set the value of 
a named entry.

When the $key argument (string) is passed, it returns the corresponding 
value (if such exists, or undef. The following two lines are equivalent:

   $val = $r->subprocess_env($key);
   $val = $r->subprocess_env->get($key);


Ok... Seems simple enough...

In my module if I do the following:

$r->subprocess_env;
my $uri = $ENV{REQUEST_URI};

The I get the URI.

But if I change the above to:

my $uri = $r->subprocess_env('REQUEST_URI');

I get undef.

Confused.

Tosh

-- 
McIntosh Cooey - Twelve Hundred Group LLC - http://www.1200group.com/