Something wrong when trading techs

I've just had something strange happen.

I was in negotiations with various AI civs to see what techs I could buy and noticed that the only one the Indians could sell me was MapMaking. The English had MapMaking and Mysticism. So
I promptly bought Mysticism off the English, and swapped back
to the Indians to see if I could sell it to them. But it still wasn't there in my list of techs to sell. I tried completely closing down all my negotiation windows and reopening just in case it was a problem with the game caching out of date data, but still no luck.

Anyone seen anything like that before, or got any idea what could be going on?

Ta

Simon

 

I heard of this before, did the Iroquios have the great Libaray? If so they would have gotten it since both you and England had that tech, if not maybe the computer cheated. Wouldn't suprise me, I think the AI does sometimes myself

 

You cant sell techs to a civilizaton that does not have the prerequistes for it, that might be your problem.