I am using Telus modem Siemens se567. the strength is good, but I can feel something fishy.

1. When I use my N800, there are some websites which are very difficulty, or even impossible to browse. I brought it to a net-cafe, it has no problem there.
2. I have no problem to use my laptop (windows XP), but occasionally MSN reports there is drop out maybe because of poor wifi connection.

I followed the instructions to change wifi channels, but there is no effect. I test net speed with my laptop using netspeed.net, the download is 1250 and upload is 500. there is no big difference when I changed wifi channels.

i called Telus, yes, they said the network is fine.

any suggestions?
thanks in advance.