file sharing on network problem

Can any one help?

I am running two laptops that have wireless NIC cards installed, both are
connecting wirelessly and perfectly to the internet ( going to the router
and then thru a cable modem)

no problems so far!

My problem is file sharing, on one machine my network places shows my shared
files on a network called "homer" - shows a folder called homer on laptop 1

so far so good

on laptop 2 I try sharing folders to the network this seems to work, but
when I go to my network places on this machine it says the following;

"homer is not accessible. you might not have permission to use this network
resource. Contact the administrator of this server to find out if you have
access permissions.

the list of servers for this work group is currently not available".

I am running identical windows XP v2 software and identical NIC hardware.

Its driving me crazy - any help would be appreciated

Pel.