Of SMC7004AWBR routers, Win2000/98se, and interal file sharing

I got an interesting problem: I got a SMC7004AWBR router (750.5435 w/
V1.42.005 firmware). I have serveral computers on my network 2
Win98se and 3 Win2000. The internet sharing works great (no problems
what so ever). My issue is with some internal file sharing. Assume
the following:

Computer A - runs Win2000 and is wireless (this is mine)
Computer B - runs Win98se and also is wireless
Computer C - runs Win2000 but is wired right into the router (this one
is driving me nuts)

Now the Comp. B, has a big ol' hard drive, so I set up a seperate
partition so we can use it as a file server. Personally, all I care
about is all the other computers being able to "see" B. I don't care
if B can "see" anyone else. Now I, Comp. A, can see Comp. B just
fine, no problems. However, Computer C, keeps saying \\ComputerB is
not accessible. The network path was not found. (Basically, system
error 53.) Now, Computer C (the problem child) can ping B and A. If
I do Start > Find > Computer, I can see the computers, but still can
not access B's shared folders.

A little about my network, TCP/IP and NetBeui are both installed,
NetBeui DOES NOT GO OVER TCP/IP 'cause I'm paranoid (see grc.com).
Computers B and C have no firewall; A does also 'cause I'm paranoid.
All computers are staticly addressed (makes making rules easier), so
no DHCP.

My insticts say, if I were to give C a wireless card, everything would
work fine. But I shouldn't have to. This should work. Any ideas???

Scott
(E-Mail Removed)