Ad Plugin DFP ad sizes - only the first defined size works?

I have a question regarding the “dfp topic list top ad sizes ”-option in for AdPlugin.

I have followed the instructions and I get it kind of working. This works:

Then I try to add more sizes, i.e. I add fluid to the list of add sizes and now it stops working.

Is this how it is supposed to work? I.e. that it ignores all sizes except for the first?