Windows 7: Networking, with Snow Leopard and Samsung BD-P4600?

I have Windows 7 set up to use Homegroup, a MacBook using Snow Leopard, and a Samsung Blu-Ray player that, supposedly, can play streaming video from files on my PC. The problem is that none of the devices can really network with the others, so far. The Blu-Ray player sees the MacBook, but doesn't see the Windows 7 box even if I give it a hint by giving it the IP address. The MacBook sometimes sees the Windows 7 box, but I can never get access to any shared folders, and it usually doesn't even see Win 7. Very intermittent, in other words. The Win 7 box doesn't see either the MacBook or the Samsung.



I'm using a Comcast cable modem and an Airport Extreme Base Station as my router. Both the Samsung and the Win 7 box are connected directly to the router via ethernet, but the MacBook is wirelessly connected via Airport. I've tried about everything I can think of to get the devices connected on a network. Is there some sort of template I can follow. I have a hunch Win 7 and Homegroup are the problem, but I can't seem to set up an alternative network because Win 7 doesn't seem to recognize anything else on the network. I'm about to give up on the project, but thought someone on this forum might be able to steer me in a more productive direction.

[Update: I set the system to Workgroup and Win 7 now has access to files on my Mac, but not the other way around. The Samsung now "sees" the Win 7 box, but when I click on it I get a message that says "No shared PCs were found." Progress, but things still don't work.]