On Wed, 15 Mar 2006 21:46:08 -0000, (Chris
Lewis) wrote:

According to Dan Espen :
"John Richards" writes:

A piece of siding in one of the two areas pulled loose within a year of the
installation and the contractor nailed it back up.

I think the simple answer to your problem is
in places where the siding has come lose, use
screws instead of nails. Deck screws should do.

I'd avoid deck screws, the underside of the flat head (cone shaped)
tends to cause the vinyl to distort and the head may slip out thru
the slot. Secondly, most deck screws have at least 1/2" of no-thread,
near the head, which means it won't grip sheathing that well.

The latter isn't a problem in this case, since OP says the
siding is going in over foam-board insulation.

according to www.vinylsiding.org/install/started.htm
you should use #8 pan-head screws.