Problem with jpgraph - graphic is damaged

[augur]

Hi.

I get some problems with jpgraph. The demo works fine, but in mantis I do net get it to work. If I try to call e.g. summary_graph_bystatus_pct.php?width=450 I get a picture back with the following text: Die grafik "summary_graph_bystatus_pct.php?width=450" kann nicht angezeigt werden, weil sie Fehler enthält.

In english: The grafik could not be shown, because it is broken. Do someone know the problem?

I already checked the php memeory limit, folder permissions,...

thy augur