What are you using for authentication? I mean, is this a home network where each computer has it's own set of users, or are you using something like active directory? I you are using AD, your mac has to join the domain.
At work we use AD, and I don't always see the servers unless I explicitly connect to them (cmd-k). But I never have any problems transferring files. I do sometimes have problems editing files while they are on the server though. I typically copy them locally, edit them, then copy them back. I never have any of these problems connecting to my linux boxes with nfs - that is very seamless.