Hi folks,
I´m not pretty sure you all (mainly FBF) gave our chinese folk an important statement: there is no disagreement between QRH and Ops Manual.
Let me try to be short: if you´re, for instance, taking off, and have such a problem, one bleed could maintain cabin pressure within limits until 25000 ft.
On the other hand, let´s suppose you´re flying at FL330. If you loose one pack, the other one should maintain cabin pressure for the remaining of the flight (that is, above 25000ft).
I hope this clears a little bit more.
Best regards,
PP