I don't say what client you are using (MS/Linux/Mac) on your PC. I haven't checked on your Router but you don't say how you are connecting to it (wired/wireless).

There aren't to many things that will effectively shut down another device on a network, but here are a couple that can.

2 Devices with the same IP
2 Devices with the same MAC
2 Devicesd with the same name

The other thing to check is virii or trojan, with the rapid emergence of wireless it is only a matter of time defore hackers start thinking of ways to commit DOS attaches on the wireless devices themselves. We are spending a lot of money to minimise our risk in this matter. A difficult thing on a public network.

Regards

Fred