Has green tea made you sick?

I guess the title of this post kind of says it all.  Captain Obvious here!

As you probably know, green tea has tons of health benefits, and some studies have even shown that drinking it daily can aid in weight loss.

As a result of all this good press, I decided to incorporate it in to my diet, specifically around 3pm when I could usually use a little energy.  I found that on the days that I did this, I had more energy to work out yet didn't feel jittery or have trouble falling asleep.

Since I was experiencing such good effects, I swapped it out for my morning coffee one Saturday before teaching.  I took it in a travel mug and headed to the ATM pre-class.  Left the ATM and boom, holy nausea!  I wracked my brain as to what I ate that was making me sick (the answer, nothing).  I continued on to the gym but was actually afraid I'd have to pull over on the highway.  I was scouting out areas with larger shoulders.  Finally made it to the gym and literally ran to the bathroom to throw up, but nothing happened.  Gradually the feeling passed and I was fine the rest of the day.

I was stumped.  Somehow I made the connection to the fact that I drank green tea on an empty stomach.  When I brought this up in conversations, I was surprised to learn that many people have felt the same way and said never to drink it on an empty stomach.

Has this happened to anyone else?

Needless to say, I won't touch green tea unless I've eaten.