Study Group assignments - no...please...don't

Maybe I've told you this before, but we are all divided into study groups of six. My group is very diverse...a doctor from Nigeria, two IT specialists from India, an engineer from Spain, a marketing specialist from LA (the only female in the group) and me.
It's fun to hang around with the group, but the diversity doesn't make working together easier.
It's a total mess actually...we argue quite a lot about the case studies that we have to prepare...and sometimes I feel like freaking out. Nevertheless, in the end we always agree on a solution for the case (well, we have to, because the group assignements are graded), but it takes a lot of time to get there. We are still in the process of setting up the rules for our case studies...different cultures can have for example very different understanding of deadlines!

I guess I will spend a lot of time with my study group during the next weeks (lots more group assignments to come).
I just hope we don't hate each other by the end of the term...