On the basis of what I have read :
Revenge and Electronic both had a promo budget and advance circa £1m. Revenge tanked and sold about 14 albums. Electronic ruled the world. Tony Wilson decided that, rather than pay Barney the Electronic royalties, to offset against the loss of Revenge and not pay Barney, they're both New Order anyway.
Come 1993, and Barney quite rightly wants his cash : the royalties which were not paid by Wilson.
Come the London deal, BS gets a larger deal as a result with Hooky taking reduced royalties to compensate for the missiing £1,000,000. For some reason, come 2006, I imagine the deal has not been renegotiated. That's my understanding. Could be totally wrong mind you, but it's called "showbusiness" for a reason.