NETWORK HELP!!!!

hey guys i have a bit of a problem
ok i have a home network set up with 3 computers 2 of the computers are wired the other one is wireless
they are all running xp
my problem
before i moved i have my laptop connected wireless to the router as with the other computer (lets call this acer) no my laptop is connected from a wire and acer is still wireless
everything works fine on the network with the other wired computer and acer
but for some reason my laptop cant see acer in my network places or in workgroups
but i have itunes running on all computers and home sharing works fine between all????????????

HELP
HELP
HELP
HELP