My N900 isn't set to use the same address at all. My desktop machines are set to use the same address and any laptops seem to have been assigned a static address!

I haven't bothered doing anything other than telling my router my N900's host name & I did specifically set my desktop machines to use the same IP but I have no idea why laptops get assigned a static IP. I'm using a BT Home Hub, version 1.5 I think.