At my club we had some tail stall situations with a Cirrus Standard
during winch launches.
With some of the lighter pilots the glider would tend to overrotate on
takeoff and when the stick was pushed forward to lower the nose it
only got worse.
Since it´s an all flying stab, pushing forward would increase the
already large angle of attack and stall the tail. A fast thinking
pilot found that a quick pull on the stick would unstall it. Sometimes
it required ´´pumping´´ a couple of times to regain full pitch
control.
After a few unpleasant launches we did a weight and balance and found
that the glider was tail heavy. After correcting this condition the
overrotation tendency was greatly reduced but it´s still possible.
I guess that´s one of the reasons they don´t make gliders with all
flying stabs anymore.

Regards,

Juan Carlos