Sorry for not having a better title...

 Can this double line be removed (Between row and child row)?
 
I have interband spacing set to 0 so there will be no space between band, but this double line is something I did not manage to get rid off. Is there a property I should change in order to do that?
 
The second  problem is removing the double header. I assume that "Frozen Headers" should solve that problem, but I didn't see a feature called like that. What do I need to do to fix that issue as well?

 Thanks