slow file copy from server to clients

I saw a strange behavior at a company which has an sbs 2003 server installed.
A file copy from the server to a client(s) goes very slow, but when I copy the file from the client to the server it goes very fast.
I didn't install this server, but I just noticed this strange behavior.
The sbs server isn't acting as dhcp server, and the clients have a static ip, so that part is already wrong, but I was wondering if that has smth to do with the slow file copy from the server to the clients.... .
I also noticed that, when I browse the clients(C$), the listing of the c-drive is also very slow.
 
server ip config:
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : HP NC7761 Gigabit Server Adapter
   Physical Address. . . . . . . . . : 00-13-21-1C-6C-98
   DHCP Enabled. . . . . . . . . . . : No
   IP Address. . . . . . . . . . . . : 10.0.0.2
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 10.0.0.138
   DNS Servers . . . . . . . . . . . : 10.0.0.2
   Primary WINS Server . . . . . . . : 10.0.0.2
 
Client Ip config:

   DHCP Enabled. . . . . . . . . . . : No
   IP Address. . . . . . . . . . . . : 10.0.0.200
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 10.0.0.138
   DNS Servers . . . . . . . . . . . : 10.0.0.2
   Primary WINS Server . . . . . . . : 10.0.0.2
 
Any idea what could be the problem?