From the information you've provided in this thread we can only conclude that 1) your elementary school used outdated educational material, and that 2) your teacher was not a rational person. Interestingly you don't need to be a rational person to be a teacher, so I am perfectly willing to accept my two conclusions as a working hypothesis.

Now, ignoring the Mercury/Pluto argument for a second, have you bothered to scientifically prove your claim yet? You've listed the four tastes (sweet sour salt and bitter), but you've clearly forgotten the asian taste of MSG, which is the fifth taste. That's right, asian pried rice, bitches.

Next, if you were to look at this illustration, you'll not only notice that there are different taste buds, but that they are all grouped together, not separated by type. Ergo the entire notion of 'taste centers' (ie that you taste sweet at the tip of your mouth) is wrong.

By the way Ceej, how goes suing your local telephone company?