Issues with subroutines and unbless references

Hi,

I'm pretty new to mod_perl/Apache2::* and I'm already struggling around with 
my first problem.

I am writing a script which later will be kind of proxy server for our self 
written application.
I need to alter/manage some of the HTTP headers sent by the application. My 
script is currently
not useable at all, though it already provides an error to me which I can't 
get rid of.

I have a subroutine "handler" where I import the HTTP object from mod_perl 
via: my $r = shift;
This works well and as expected. But if I wanna use that object later on in 
a different
subroutine, I get the following error message everytime I try to use the $r 
object in the
subroutine: "argument is not a blessed reference (expecting an APR::Table 
derived object)"

Here is a code example of what I've written:

====================== begin code snippet =================================
## The main program handler // handler() {{{
sub handler
{

        ## Get HTTP Apache object
        my $r = shift;

        ## Get a log object
        my $log = get_logger( 'handler' );

        ## Log a start message
        $log->info( __PACKAGE__ . ' successfully started.' );

        ## Get allowed headers as hashref
        my $headers = getAllowedHeaders( $r );

        ## Exit gracefully
        $r->content_type( 'text/html' );
        return Apache2::Const::OK;


}
# }}}

## Extract sent HTTP headers and extract the allowed ones // 
getAllowedHeaders() {{{
sub getAllowedHeaders
{

        ## Get Logger object
        my $log = get_logger( 'getAllowedHeaders' );

        ## Get HTTP object from caller
        my $r = shift;

        ## Define a temp. header hashref
        my $header;

        ## Go through the list of allowed headers and check if the are 
defined {{{
        foreach my $head ( sort ALLOWED_HEADER )
        {

                ## Check if the HTTP object has the corresponding header set
                next unless defined( $r->headers_in( $head ) );

                ## Extract value from HTTP object
                my $value = $r->headers_in( $head );

                ## Log a debug message
                EXT_DEBUG && $log->debug( 'Found allowed HTTP header "' . 
$head . ' with value: ' . $value );

                ## If the header is defined in the HTTP object, store it for 
later usage
                $header->{ $head } = $value;

        }
        # }}}

        ## Return the hashref
        return $header;

}
# }}}
====================== end code snippet =================================

Whenever I call the "$r->headers_in( $head )" in the getAllowedHeaders 
subroutine I
receive the error message about the unblessed reference.

Any hint about how to fix this issue would be greatly appreciated.


Thanks
Winni