just a stab in the dark... but, i think it may be because your phone line is through SKY (if it is) and may no longer be on BT's system as it now belongs to sky? just a guess like I say... your sky phone & broadband is probably MPF LLU and I wonder if its related, like u say the phone number checker wont work cos its not on BT or BT WLR3, its on SKY's own network & hardware (SVBN) - I know the address checker should still work perhaps but that may be part of the problem here, sky have the phone number for that address, as its full MPF LLU the address also may have been removed from BTo database
I remember similar thing when your on Talk Talk and you enter phone number into ISPs websites to see if you can get broadband and it says unavailable or number not found because talk talk own the number and looked like it was removed from BTo's database.
there is also the possibility that you (for whatever reason) are fed from a different cab, although unlikely if every house in the street can get it. (which ash already been suggested)
are any of your neighbours on Sky Phone line and does their address come up trumps for fibre?
Like I say I may be wrong and just putting it out there
Edited by paulb100 (Fri 06-Apr-12 14:48:36)