yeah cheers for input guys.
Someone at Skyuser has got back to me and confirmed that the username and pass from a Sagem 2504n V6 work with fibre and also the older 2404 aswell - so i should be covered.
I have 2504n incomming off ebay for a tenner so its no biggies.
I've got a another query now though....
Can a Sagem 2504n V6 be used actually on the Fibre service ?
I'm thinking of using initially that when the BTO eng comes to install (then swap for my 3800 running DD-WRT when he leaves)
This way i can sell my Sky hub unopened