Landing with one spoiler

I committed one of the worst errors - an incomplete preflight check.
I did not check the hotelier locks to the spoiler rods with enough care
before takeoff. Coming into the pattern I extended the spoilers and
noticed immediately that something was wrong. The glider (SparrowHawk)
was pulling to one side and the rate of descent was not as much as I
expected. However the glider was easily controllable. A few seconds and
I saw that the right spoiler was not deploying. What to do? A couple of
attempts to close and open the spoilers did not actuate the right
spoiler. Then, oh well, lets check and see the effect of landing with
only one spoiler. The situation was less dramatic than expected.
Maximum sink rate was halved and the SparrowHawk needed some cross
control to fly straight but no problem. The landing was easy and
controllable. The lessons to be learnt from this are 2 fold: 1) landing
a glider with only one spoiler should be easy for most pilots and 2) do
a serious preflight inspection especially after assembly.
Dave