Okay Luis no problem. As for the symmetrical aerfoil issue. That is an easy one. The answer is yes, even with a high angle of attack, a symmetrical aerfoil can stall! Easy way to test this one. Take a RC model with this aerofoil and slow it down, sooner or later it will stall and the airplane will fall. I guess a little more explination is in order.

Lift is made perpindicular to the chord line. Can you have a wing flying with a high pitch angle and still be tracking forward, anyone that has seen an F16 doing a slow flyby will attest to that. Okay, the forward motion of this plane is the relative wind, and since the chord line in this example is pointed very high, this causes lift to go rearward and resist motion forward. At this point if the pilot pitches the airplane up, they will notice that the airplane will slow down and a loss of lift occurs. This is do to the fact that the wings are producing as much lift as possible. At this point power becomes the factor governing lift, and pitch governs airspeed. If the pilot then continues to pitch up, the "critical angle of attack" will be reached. The critical angle of attack is the point at which a wing can no longer create lift.

The experiments that I have participated in were mostly for school projects; therfore I don't have much of personal information other than what I have seen. Now as for as NASA goes, that should be rather easy to find, and I will do my best to get this info for you in the very near future.

Another place that is a wealth of knowledge on this matter can be found with the Aircraft Owners and Pilots Association. This is a group that supports the needs of new pilots, and to Certified Flight Instructors of the full scale aircraft. I have seen videos that show some of tests done by NASA for AOPA. One such video shows the effects of wind over the wing as it relates to wing stall. They tied hundreds of little streamers on the top of a wing. While in flight the streamers stay attached to the wing by the realitive wind. As the airplane was slowed down, AND pitched up, you could see the air starting to seperate from flowing along the wing by the streamers starting to blow in every which way, including forward. At the instant the streamers on the leading edge of the wing started to sway, the wing stall and lift was lost!
I din't participate in the actual test that AOPA video taped, but I have replicated this experiment in college.

Again, I'll get something to look at soon (sorry don't have the time any time to dig into it right now.)

Reg