XP office network/workgroup issue

I have four computers on a workgroup, all wired directly into a wireless router. I need to add a fifth but there are no more cat5 ports on the router. So, the fifth connects via wireless and the four other connect with cat5, but all 5 are technically connecting through the same router.
I can get the 4 on a workgroup (mshome) no problem. The fifth wont show up. It shows it's own workgroup (same name, mshome) but it doesn't see the other computers.
Please help.

re: XP office network/workgroup issue

What is the make and name of that router? You may have to set it up somehow to combine the two networks.

Greetings,
Nepomuk

re: XP office network/workgroup issue

It is a Linksys. Wireless-G Broadband Router. Is it separating the networks just because the one computer is connecting via wireless? they are all on the same router.