Villas,
Please check my previous post, I revised.
I was told by an instructor but now I assume (according triple ADR fault ECAM-no altitude limitation) that this is not correct about mach effects.
Feather44,
You have messed up BUSS availability together with unreliable speed procedure, ALL ADR OFF procedure (non BUSS aircraft) and ADR 1+2+3 Fault (BUSS equipped a/c only)