Be careful with IP Helpers & Windows networking.....
By default Cisco Routers forward 9 types of UDP broadcasts when IP Helpers are enabled - DHCP Client & Server broadcasts, TFTP, nameserver, DNS, NTP, NetBIOS-ns, NetBIOS-dgm and Tacacs. If you leave these enabled then Windows NetBIOS gets upset and you will see Master Browser errors and usually intermittent Browser issues (Windows networking NOT Internet Browsing). This is because the Browser announcment broadcasts are forwarded to the IP Helpers.
You should disable all UDP broadcast forwarding except DHCP using the following in globacl configuration:
no ip forward-protocol udp tftp
no ip forward-protocol udp nameserver
no ip forward-protocol udp domain
no ip forward-protocol udp time
no ip forward-protocol udp netbios-ns
no ip forward-protocol udp netbios-dgm
no ip forward-protocol udp tacacs
You need to ensure your Windows Name Resolution works throughout your Routed network, this generally means WINS & DNS. In a lot of networks you can disable WINS and NetBIOS over IP (NBT) but check your applications don't need NetBIOS first....
HTH
Andy