A minor annoyance, but I always thought the name of this spice was
spelled and pronounced "turmeric". It even says so on the bottle I
have in my cabinet, but all tv chefs pronounce it "tumeric", including
the Iron Chefs, Alton Brown, and the competitors on all the "reality"
cooking shows.

Here's a link: http://en.wikipedia.org/wiki/Turmeric

Whenever I hear it pronounced "tumeric", I can't help thinking of
tumors.

Shouldn't professional chefs, food scientists, writers and critics
learn the proper names of their ingredients?

I may be nit-picking but I think I'm right on this issue.