Hey r0bErT4u, why are you so stuck on titanium prop shafts? (I've seen a few post by you concerning them.) I would think that titanium shafts could introduce problems that you may not have considered. My guess is that they are probably weak by design. Stronger shafts would probably mean breaking motors or motor housings and possibly damaging the cross during a crash. The shafts are relatively inexpensive and are easily replacable. Replacing motors or crosses would definitely be more expensive, as well as, time consuming.
This next statement is not intended to offend but if you're easily offended, I apologize now.
You sound like the dog relentlessly chasing the skunk. He puts all of his energy into catching that black & white beauty. But, when he catches his "prize", he soon realizes that he really didn't want what he thought he wanted.
You may "think" unbreakable (or nearly unbreakable) shafts are the answer. But when you have to start replacing more expensive parts, I think you'll see the advantage to having a "weaker link" in the chain; an inexpensive link. It's just like having fuses or fuse links in an electrical circuit.
Just saying....
AR Drone 2.0: Hardware: 2.1 | Software: 2.1.16
Inertial: Hardware: 2.3 | Software: 5.32
Free Flight: 2.2.7 | Flying with: iPad 2