  Irreducible background effects due to $e^+e^-\to W^\pm + bbjj$ and $e^+e^-\to
W^\pm + jjjj$ events produced via QCD in top-antitop production and heavy Higgs
searches in the bremsstrahlung channel are studied at the Next Linear Collider.
Various distributions relevant to phenomenological analyses are given and
compared to those expected from top and Higgs signals in the decay channel
$b\bar bW^+W^-\to b\bar b W^\pm jj$. This analysis follows similar ones
previously carried out for the case of the irreducible background proceeding
via electroweak interactions
