Sky setup using ext leads - Help

[techtwin]

I really need help with set up sky box in living room and sky box in sons bedroom. I have been talking to Sky technical last weekend and this with no result....
Sky can do a system check fine but both boxes fail on final check which is call back to Sky.
Living room box is connected to telephone ext lead which plugs into a 3 prong adapter. 1 prong has this ext 2nd prong has landline telephone and 3rd prong is spare. This adapter is connected into a DSL filter and that is plugged into the master telephone socket.
Sons sky box is connected to a telephone ext lead which runs into spare room tel socket which also has a DSL filter on it which has this extension clipped into it and the modem connection for the computer which is AOL/BT.
I hope this is clear enough. Please advise if this is correct ? if not how should it be setup ? Anyone any suggestions I would be grateful as at wits end now with Sky.

[lincsat]

I've come accross this many times - Some DSL filters do block the Sky modems, try switching off your ADSL modem and disconnecting the filters, plugging the SkyBox directly into the phone line and try the callback again
.

I've also moved this to the correct section.

[techtwin]

Hi Lincsat, thanks for reply. Just dragged tv across living room to get box direct to phone line but still failed on call back. I cant do this in sons room as no telephone point. I did ensure modem was unplugged from p.c. Any other suggestions, still got tv in middle of room just incase