This is a little bit different from the case of reusing boilerplate text.
Say one has done a series of experiments (either real or "virtual") to produce a set of results. Because the results are inconclusive as to the cause of certain effects, an additional, much larger set of experiments were performed under a series of different conditions to complete the "factorial matrix" of possibilities (all possible states of factor X crossed with all possible states of factor Y).
However, because the original results are valid, and represent unique "cells" in the factorial matrix, is it necessary to rerun the experiments for a future publication, or is it just a matter of obtaining journal permission for the re-use of figures and tables associated with the presentation of the data? As an example, am I violating copyright if I add a new set of curves to a figure which contains the same data as before?
I ask in part because there was just today a retraction based on reuse of figures, and I'd rather not run afoul of guidelines.
I agree with the other answer that this is a normal occurrence.
To avoid any confusion, be clear and cite the previous publication as the source/original presentation of the data. It is not citing (even yourself), which is an ethical breach, as it makes it seem that have done more than you really have.