Since for you the Memory Supercharger caused the headache I am going to guess that you were trying too hard to listen to both voices at the same time. Because this creates confusion as it is designed to do you are getting tense trying to follow what is being said.
When it comes to listening to the Paraliminal don't try to follow either of the voices and just let your attention go down the middle. You might find yourself listening to one voice for a bit and the other for a section and that's fine.
Remember to breathe. A stuffy room, tight fitting clothing that cut off circulation can also create a headache. Drink a glass of water prior to listening. As already stated this is a possible reason. (yin yang water is not necessary and probably doesn't mean much you unless you happen to be a practioner of Spring Forest Qigong)
If the Paraliminal continues to give you problems continue the course without it. It's a fine resource for helping to learn anything (not just PhotoReading) but it is not an absolute necessity for learning to PhotoRead. So there is no reason to give up learning to PhotoRead.
Keep us posted on your progress.
Alex
