Thanks guys.
Above i mentioned the flocking creatures that i couldn't make because of problems.
I should get some sleep but i got curious and made some tests.
This is the old thread about the problem (if it is the same one):
https://planetside.co.uk/forums/index.php/topic,21503.msg216279.html#msg216279[attach=1]
I haven't read all what we wrote in that thread, but it looks like the same problem happens
even if you only change the values in the "Area rotation" option in the populator itself (with the object Transform values unchanged).
This is with Windows 10 64bit, Terragen 4.1.18 64 bit.
The same problem was in 4.1.15. I installed 4.1.18 just because of this problem yesterday.
Is this the same old bug?