GMAT Strategy

I've done the GMAT Prep 2 CAT and I had the feeling that the questions were really hard during the verbal but I scored only a 34.

The wrong questions were 5, 7, 8, 26, 27, 29, 30, 37 and 38.

As you can see, there weren't so many and also, they are that together (i mean, is like there is space between the wrong ones).

Why is this?
Is it because in the first 10 I screwed on 3 and then the algorithm doesn't let me go over a score of 40? Because those on 26-30 really dumped me down? Another reason??

Thanks in advance!

Regards.

I don't think anyone can really answer this because the CAT system is so complex.