i have had the same thing with the peanut lab, get booted in the middle of the survey or toward the end.
I try to avoid the peanut lab because of that reason and (because of the name 'peanut lab', maybe they have a chimp that runs the show 'Bonzo') so, It's not the greatest.
I see they offer short surveys lately that take a couple minutes and 'freeze' a blank page so they are pizzin me off a little too.