  We present phase-resolved spectrophotometric observations of VV Puppis
obtained during two different states of accretion. We confirm the detection of
cyclotron lines from emission regions at both poles (Wickramasinghe et al.
1989) having significantly different field strength of B_1 ~ 31MG and B_2 ~
54MG. Our phase-resolved data allowed the detection of phase-dependent
wavelength shifts of the cyclotron lines from the main accretion pole which is
due to the varying aspect of the observer. A corresponding motion of the
cyclotron lines from the secondary pole appears likely. Compared to 1984, the
cyclotron lines from the main pole appeared redshifted in 1989, during an
episode of higher system brightness. This shift can be explained assuming
either different locations of the accretion spot and, hence, variations of the
magnetic field, or variations of the plasma temperature both triggered by
variations of the mass accretion rate. The cyclotron lines from the second pole
do not show such changes suggesting that the coupling region for the weakly
accreting pole is more or less stationary whereas the coupling region of the
main pole varies in space, most likely depending on the mass accretion rate.
