There is indeed an error in bipolar not floating: it outputs double voltage. Solved at Rev 1537.
Anyway bipolar not floating is 2 phase at 180ยบ, so you can't connect one output to ground. The proper way to use it is just connect the outputs to the transformer primary.
And I was wrong about "not floating". This mode does not output AC. It is useful to add waves, for example like this:
In the last one (floating) the op amp supply voltages are not ok, should be at least 0 to 10 V, but better more. To test the "floating" functionality you can do something like this and change the sourse voltage:
The previous one is unipolar and is working ok for me.