  We present new optical spectroscopic observations of U Geminorum obtained
during a quiescent stage. We performed a radial velocity analysis of three
Balmer emission lines yielding inconsistent results. Assuming that the radial
velocity semi amplitude accurately reflects the motion of the white dwarf, we
arrive at masses for the primary which are in the range of M_wd= 1.21 - 1.37
M_Sun. Based on the internal radial velocity inconsistencies and results
produced from the Doppler tomography -- wherein we do not detect emission from
the hot spot, but rather an intense asymmetric emission overlaying the disc,
reminiscent of spiral arms -- we discuss the possibility that the
overestimation of the masses may be due to variations of gas opacities and a
partial truncation of the disc.
