network name resolution

I just switched, bought a macbook with Leopard installed. I still own a few windows machine and Buffalo network attached storage, all of which are connected together via a Linksys wireless router.

After much fiddling, I managed to be able to see my NAS from the finder, along with all the other windows share. So file sharing works, albeit by fully opening the firewall.

My problem is that I can't browse to the NAS. From my windows machines, I just type the hostname in the url bar ( http://mynas). But in Safari, I get a "server not found" error. Same thing with Remote Desktop Client, it won't connect to my windows machine by name only, I have to specify an IP address.

So the finder can find the machine, but nobody else can resolve the name. On the other hand, if I go into a terminal and type this:
$ nmblookup mynas

I get mynas's IP address, so it is known by samba.

So how can I tell Leopard to use NMB or WINS to resolve hostnames before it tries other sources?

Thanks

-Mathieu