But on my mum's computer (it's completely fine on my laptop here) Firefox doesn't seem to be able to get a connection anywhere. Full stop. Not even to access the setup pages.

IE and Opera work fine.
Pings are fine.

Using DHCP on mum's computer.

I've tried using the MT882 plugged in directly, and MT882 -> WRT54G (which is my intended setup).

Tried disabling and enabling all the protection software as well, so I've been left stumped.

Hopefully I get this solved by night's end, or else I've got to put back my old D-Link back Frown