With it being in a for loop and not being able to see the other frames in your sequence structure, I'm just guessing that you're sampling too fast. Turn off autozero and autorange and see if that makes a difference. Add some delay between measurments. You could also try software triggering.
p.s. You should be using a shift register to pass the error cluster between iterations of the for loop and if you used the flat sequence structure (or better yet no sequence structure at all) it would make all of your program visible.
