ios transform.rotation.y breaks up window - objective-c

Question

I have an odd problem in one of my chain animations. I have block object for each of the blocks on my screen (26 of them), and when the user presses them I perform a flip. It works great, but I'm adding a scale animation before I do these to make them about 50% bigger on the screen. So, my sequence is:
enlarge
delay (let user see the large image)
spin-out 90% (removes block from view) - using transform.rotation.y
change image & spin-in
shrink.
I have setup the window view controller to be a delegate of these blocks, such that it can pass a counter to the blocks so I can position the right sublayer on the top (using setZposition).
It all works great, except when I have 2 blocks on positioned above/below each other on the screen, such that the enlarge will cause them to overlap, and then when the spin-out animation starts, it immediately has the right side of the block pop behind the block below it. I've tried changing the animation to transform.rotation.x and get the same behavior when the blocks are side-to-side.
I'm not sure if it's an iOS bug of if I'm just not doing something correct. Any suggestions are greatly appreciated. Here is the spin-out method:
- (void)spinOut:(id)sender
{
NSTimeInterval animationTime=0.85;
[UIView animateWithDuration:animationTime
delay:0
options: UIViewAnimationOptionCurveLinear
animations:^{
// setup the animation to spin the current view out
[CATransaction begin];
[CATransaction setDisableActions:YES];
CABasicAnimation *spinOut = [CABasicAnimation animationWithKeyPath:#"transform.rotation.y"];
[spinOut setDelegate:self];
[spinOut setDuration:animationTime];
CAMediaTimingFunction *tf = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
[spinOut setTimingFunction:tf];
[spinOut setFromValue:[NSNumber numberWithFloat:M_PI * 0.0]];
[spinOut setToValue:[NSNumber numberWithFloat:M_PI * 0.5]];
[spinOut setRemovedOnCompletion:NO];
[spinOut setFillMode:kCAFillModeForwards];
// setup variables used to roll in the next view on animation completion.
[pageView.layer addAnimation:spinOut forKey:kMyVeryOwnABCsSpinOutKey];
[CATransaction commit];
}
completion:^(BOOL finished){
[self setFlipOutAnimationTimer:[NSTimer scheduledTimerWithTimeInterval:animationTime target:self selector:#selector(spinIn:) userInfo:nil repeats:NO]];
}];
}

Answer 1

OK - this is an old question, but I kindof figured out this problem. Since I was flipping these images around the Y axis, I was able to change the animated image's Zposition. In my startAnimation method, I added:
float pageLevelLayerPosition;
// logic to set the zposition variable 100 more than anything nearby
_originalImageViewZPosition = bigImageView.layer.zPosition;
[bigImageView.layer setZPosition:pageLevelLayerPosition];
and then when in the animationDidStop, I added the relevant line of code to reset it back to 0 where I was removing the animation. I had some code to manage the variable so that I was assured that the number was greater than anything nearby.
I guess if I ever get into 3-D animation, then I'll need to control this much more closely, but that is what was causing my problem.