It is possible that the ground state DFT calculation has been done with a position of the coordinate system corresponding to low symmetry. This is not good as the band-structure calculation would require more -points. To get around this without repeating the ground state calculation, one should recalculate the density with respect to the ``shifted'' coordinate system.
This is done here. You will be asked about the position of the new origin of the Cartesian coordinate system (in Å). Then the density will be recalculated. Note that the old density will be destoryed. You can save the new density using option 9 of the density menu, Section 3.6.3.10 .