Yep, AvP opened big, then sank like a stone. However, there's only two figures that the studios care about these days:
$38,291,056 - Opening weekend (mainly for bragging rights, it seems)
$103,873,228 - worldwide box office
Weighed against the $60 mil budget, plus another estimated $35 mil advertising, AvP is a "hit," however marginal its profit might actually be in the real world. Hence Anderscum gets to gleefully ply his uberhack talents on the franchise some more.