bug in join

With following two simple files:

test1:
a	f
b	h
c	g

test2:
1	b
2	g
c	6

join -j 2 test1 test2

gives the wrong result which is nothing.

The correct result should be:
G	c	2

- Haidong
http://www-cs-students.stanford.edu/~hdwang/