  In the BFKL approach, discontinuities of multiple production amplitudes in
invariant masses of produced particles are discussed. It turns out that they
are in evident contradiction with the BDS ansatz for $n$-gluon amplitudes in
the planar $N$=4 SYM at $n\ge 6$. An explicit expression for the NLO
discontinuity of the two-to-four amplitude in the invariant mass of two
produced gluons is is presented.
