[Hampshire] Wireless problem, not strictly linux related

Four laptops, 1 XP, 1 Win 7, 1 Macbook, 1 Linux, all had working wireless
connection before router change.

The new router is a Draytek 2710n, wired connection through the router works
perfectly, the Windows 7 laptop connected over wireless straight away, after a
few hours of huffing and puffing the XP laptop suddenly found the internet
although I am not sure what it was that made it work.

The Mac and the Linux laptop will connect to the wireless, the router show they
are connected but they won't pass any traffic over the wireless. If I make
changes to the wireless settings on the router, the linux box drops the
wireless link and will then re-establish the connection but still no traffic
pass over the link to the internet or local network (like ping, I know this is
a contradiction as it is picking up dhcp and the wireless its self). I have
tried all 11 channels but still nothing (on some of the channels the linux
laptop won't even see the wireless network, this is the same as it used to do
on the old wireless network). I have set the mode to mixed 11b and 11g, still
nothing.

The linux laptop is getting its IP address via DHCP from the router (can't
confirm with the MACbook as I don't have to hand at the moment). Neither the
macbook or the linux laptop can ping the router over wireless let alone
anything else.

The new router is running a different ssid and IP range to the old wireless
network.

I have spent several hours last night and today on this, any thoughts??

Tim