Why not turn on "IDENTITY_INSERT" for that table instead during the duration of the insert? I assume the reason you want to turn off the identity property is becuse you want to insert some values into that field? Look at BOL for "IDENTITY_INSERT".
Tim C.
//Will write code for food
One Windows to rule them all, One Windows to find them,
One Windows to bring them all and in the darkness bind them
In the Land of Microsoft where the Shadows lie.
Tim C //Will code for food