You definately can't use any kind of splitter with a satellite STB/LNB. This is because the LNB is an active device, controlled by the STB. The proper way to cable a Sky+ box is with a multi LNB. Sky use quad LNBs but only connect two of them. You can't multiplex the signals either. You need two discreet cables from each LNB output to each STB input.
BTW. Even when you have it connected, in order for the box to work as a PVR you have to have a Sky+ subscription which is ten quid on top or your existing subscription, unless you have the top package. There is no way around this.
Terry, March 2006