xp pro and xp home not talking on network

I have set up my network on my xp pro machine. The 2 xp home machines (desktop and laptop) are able to print over the network to a printer and connect to the internet.
My problem is I cannot see any of the shares on the computers all the time. From time to time I can see all the computers, other times I can’t even see the machines when I try to map network drive.
I have read post after post and tried many thing to get this to work.

Can people give me more things to try to get my machines to network and share files all the time…

thanks