Thank you all for the response - especially Patric and Shawn ;-P Shure,
I could use two of such landings to fulfil my 10 fligh requirement (NOT)

To BTIZ: I got some thorough checkout after that "incident" and I don't
plan to do it again. Both, the instructor as well as the owner of the
school made it rather clear that this is the way to break off the tail
booms, squash some of the front weel attach point, or do some other bad
thing to the Grob. I am now rather careful to land by the numbers an fly
a very stable approach (at best as I can).
This is also a different experience than flying the C172 with the "pilot
being optional" ;*) The Cessna is much more tolerant to pilot
confusion than the Grob with this respect.

Chris