Slide-only view and 4:3 limitation

I normally publish courses with the sidebar/nav turned on, however I have a special project that will require no navigation at all. I switched to the slide-only view in Presenter (09, if it matters), but since the only supported screen sizing option is 4:3, I end up with blank vertical space on either side of the "stage."

Is that simply a limitation I have to deal with, or is there some work around I haven't been able to find here?

Thanks.