  Let X be a P^1 scroll (a compactification of a line bundle L) over a complex
surafce S and assume S has a global two form with zero loci a smooth curve C.
The Donaldson Thomas invariants of X is shown to be zero if the curve class has
is component on S not a multiple of [C]. For nonzero case, when the prime field
insertion are above C, the invariant is shown to depend only on the analytic
neighborhood of L in X.
