Thanks Matt, that was the problem, indeed.
The tree object was set up in a row with similar trees with different polygon count.
I must have copied it from there without properly resetting it to the origin of the workspace.
And now, much later, I only quickly looked at the numbers - which were 0,0,0 for the pivot of the tree and did not notice the polygons were way of.
Not centered on the pivot. Stupid mistake actually...
Ok, everything back to normal then...even though the flying trees looked quite nice
I must keep that "trick" in mind.
Thanks everyone for their thoughts.
CHeers, Klaus
ps: the "lean" factor settings are still quite extrem, that`s why the fat guy is tilted all over the place so much