[SOLVED] Online Definite Integral Calculators faulty?

Hi all,

I've been looking at two online calculators of Definite Integrals and I'm wondering if they *can't* handle limits that cross the x-axis

eg.

$\displaystyle \int_{-3}^{1} \! sin(x) \, dx.$

My solution is that the area is 2.4486 (being 1.989 + 0.459 area below axis added to area above axis)

But if you use either of these two popular online Integral calculators

Find the Numerical Answer to a Definite Integral - WebMath

Definite Integral Calculator at SolveMyMath.com

they give a result of -1.53 (negative area subtract smaller positive area)

So are they wrong? or is there a different purpose for this negative result?

Cheers (Coffee)