Problem with Networking, half works, half doesn't

Hi all,

I'm new here and have really got a head scratcher. I currently have a network setup like follows

Internet > Orange Broadband (Livebox ADSL) >(ethernet)> Linksys WRT54GS >>>>

Macbook (Wireless)
Vista (Wired)
XBox 360 (Wireless)
Printer (Wired)
Mobile Phone (Wireless)
XP Laptop (Wireless)

So here's the problem, I cant connect with Vista or my mobile phone, everything else works fine. Everything is DHCP enabled however i have tried using static IP's and still no luck. I am running the latest firmware on both routers as well as updated drivers for all computers. I can also access both routers config pages from Vista and the Phone but it's only these that won't pick up the internet. I factory reset both routers yesterday and managed to get it to work however i woke up this morning and Vista/Phone no longer work. It seems silly that i can access the internet and config pages with mac, xp, xbox etc but on the others get refused access to the internet even though i'm blatantly connected to the network. Are there any settings that i'm overlooking that would lead to this.

Any help will be greatly appreciated.

Thanks

Justin