iOS7 - UITabBar - Transparent doesn’t work

Question

I m using custom UITabBar in my app and i set the translucency to NO:

if ([self.tabBar respondsToSelector:@selector(setTranslucent:)])
    [self.tabBar setTranslucent:NO];

I have UIViewController with this .xib:

In the white area i have a UIScrollView with UIEdgeInsetsMake(0, 0, 70, 0) as u can see.

My problem is that the UIViewController doesn't shrink because of the UITabBar, and the UIEdgeInsets is 70 points but starting from the point 480, rather then 410 (480-70).

I want that the 70 points will start from the highest UITabBar point (UITabBar high is 49 points), point 480-49 = 431.

Any help will be great!