Read a lot, Still Have Problems

hello everybody!
I have an encore router, 2,5meg adsl ppoe connection.
THe adsl modem plugs to the wan port in the router, and from there it goes to 2 computers. Most of the time one computer is off.
The problem i have is this: some pages takes AGES to load, (like cnet.com, apple.com, etc) for example, when i download itunes, it downloads at 300 bytes/sec!! 8O
What could it be?
I have only opened the emule ports.
Here Is some of the settings---
Thanks !!!

LAN Settings
IP Address . . .
Subnet Mask 255.255.255.0
The Gateway acts as DHCP Server Enabled
IP Pool Starting Address 192.168.10.
IP Pool Ending Address 192.168.10.
Lease Time One day
DNS Proxy Enabled

ALG(Application Level Gateway)
FTP no
H323/netmeeting no
PPTP passthrough yes
Windows messenger(file transfer) yes
ipsec passthrough no



Routing Table

Destination LAN IP Subnet Mask Gateway Metric Interface
0.0.0.0 0.0.0.0 200.3.60.3 0 ppp0
192.168.10.0 255.255.255.0 192.168.10.0 0 eth0
200.0.0.0 254.0.0.0 201.252.165.154 0 ppp0
201.252.165.0 255.255.255.0 201.252.165.154 0 ppp0

yes, i disabled the firewall in the router and now it works, but i dont know ho to have te firewall enabled and make it work.