  Context. The relation between solar surface rotation and sunspot activity
still remains open. Sunspot activity has dramatically reduced in solar cycle 24
and several solar activity indices and flux measurements experienced
unprecedentedly low levels during the last solar minimum.
  Aims. We aim to reveal the momentary variation of solar surface rotation,
especially during the recent years of reducing solar activity. Methods. We used
a dynamic, differentially rotating reference system to determine the best-fit
annual values of the differential rotation parameters of active longitudes of
solar X-ray flares and sunspots in 1977-2012.
  Results. The evolution of rotation of solar active longitudes obtained with
X-ray flares and with sunspots is very similar. Both hemispheres speed up since
the late 1990s, with the southern hemisphere rotating slightly faster than the
north. Earlier, in 1980s, rotation in the northern hemisphere was considerably
faster, but experienced a major decrease in the early 1990s. On the other hand,
little change was found in the southern rotation during these decades. This led
to a positive asymmetry in north-south rotation rate in the early part of the
time interval studied.
  Conclusions. The rotation of both hemispheres has been speeding up at roughly
the same rate since late 1990s, with the southern hemisphere rotating slightly
faster than the north. This period coincides with the start of dramatic
weakening of solar activity, as observed in sunspots and several other solar,
interplanetary and geomagnetic parameters.
