[otrs] Can't locate object method "png" via package "GD::Image"

Hello, I'm running OTRS 2.0.4 on a Fedora Core 2 server with perl-GD installed via rpm. However, when I go to the statistics page I get the following error: Can't locate object method "png" via package "GD::Image" at /opt/ otrs//Kernel/Modules/SystemStats.pm line 330. However rpm -qi perl-GD (version 2.30 from Dag) tells me: perl-GD is a Perl interface to the gd graphics library. GD allows you to create color drawings using a large number of graphics primitives, and emit the drawings as PNG files. So I guess I should have png support in my perl-GD package. Does anyone have any idea why the png object method can't be located? Thanks, Nils Breunese.