I guess this has to be a question, first. Are you working on integrating Daterange with the Date 2 API?
I haven't had any problems (except for the one that you quickly fixed months ago) when I was using Date 1, but now that I'm using Date 2 rc3 and can't use this module for some views because of problems with granularity. Others work fine. I haven't really debugged to know where the problems lie, but the first step is to find out:
Will it be updated to completely work with Date 2?