I'm creating a custom stack graph...
I hit Custom Graph... Add, fill it in..
Click on the name of the graph and I see an empty graph above it..
I add an item, set it to stack and the image link breaks.
I change the said item to a line graph, and I see the data..
I set it back to stack and the link breaks again...
'Stack' types need to be stacked on top of other types of graph items. Commonly there is an 'area' on the bottom (ordered at the top of the list) followed by any of the stack items.
Since we have the opportunity to cover up this misfeature of rrdtool, I've started bug#383
to address it.