  The dimer-plaquette chain undergoes a first order transition driven by
frustration to an orthogonal dimer ground state. We analyze the magnetization
curve in this orthogonal dimer regime. Besides of the recently found
magnetization plateaus at m=1/4 and the m=1/2 we find an infinite sequence of
plateaus between m=1/4 and m=1/2. These additional plateaus belong to
magnetizations m(n)=n/(2n+2), where n is a positive integer number.
