'Grouping field' in format settings adds a new line on each save

Hi,

I notice that everytime I save the format settings of my view, and I open it again an extra line is created for the grouping fields.
None of those have a field selected (and that is the idea!), it starts to be inconvinient because one of my views now has 28 lines for grouping fields and on all of them nothing is selected. Even if I change nothing on the format settings and click save (not cancel) there is an extra line created.

At this specific case I'm using content panes and a jQFX format. However, I notice that changing that does nothing to the issue.

Can you have look into this bug. Its not a real problem, but very inconveniënt over time.

Thanks in advance!

Regards,
Peter