FLOW sorting question

I'm trying to isolate the top 10% of the brightest and bottom 10% of the dimmest cells.

After the sort was finished, I ran the sorted cells to check if I sorted the populations I was gating. The dim cells look good, but the bright cells have a much broader distribution that I expect -- It's almost as if I'm not gating the bright cells at all. Any ideas about what could be causing this?