It' the stright table bheavior.
I've solved this with a little work around...may be usefull also for you.
I create two tables:
- One that doesn't shows total line and that is splitted in several pages.
- A second table that showes only the totals and I placed it in the appendix page section.
By this way I avoided the problem you described, but you have to mantain two tables instead of one.