A Threefold with pg=0 and P2=2

We construct a nonsingular threefold X with q(1) = q(2) = p(g) = 0 and P-2 = 2 whose m-canonical transformation phi(vertical bar mKx vertical bar) has the following properties i) phi(vertical bar mKx vertical bar) has the generic fiber of dimension >= 1, for 2 <= m <= 5; ii) it is generically a tranformation 2: 1, for 6 <= m <= 8 and m = 10; iii) it is birational for m = 9 and m >= 11. So, we have a gap for m = 10 in the birationality of phi(vertical bar mKx vertical bar).