Mariska Poiesz

I have been having trouble training with one of the other students at our dojo.
When we train together I find it very difficult to practice the technique asked of us on him. I feel as though he is risting too much for technique's to work, but maybe I can't get controll over the situation because my technique is bad.

For example, yesterday we were practising morotedori iriminage. He places a very fierce morotedori that quickly moves into a yonkyo. That yonkyo still hurts the next day.
From that attack I can move into a kotegaishi or an ikkyo, but not directly into an iriminage. (Kokyonage is also difficult with him) I've asked him to calm down a bit so that I can figure out the best approach to his attack, but even then I feel as though I am not executing the technique right, and other techniques seem to make more sense when dealing with him. When we speed up again I can barely apply the iriminage and I have to use strenght. However my iriminage seems to work with other people.

After class I've spoken to some other people about him and they also find him a difficult and anoying training partner.

Am I being too sensitive?
Are other uke's not resisting enough during my irimi, making me think I can apply the technique while in reality I can't?
Or if his way of taking ukemi is the problem, how can we get him to ease up and relax?

We are both 4th kyu, going for 3rd end this month.