Hi Janko!
In the meantime I also got the instructions how to subscribe to main Gemstone mailing list, which is recommended for more general GS problems, like yours:
http://earth.lyris.net/cgi-bin/lyris.pl?enter=gemstone-smalltalk
Here you won't need to wait I suppose :)
Thank you very much for your help, I had a look into the GemStone/S bug note DB - and you had been right - it was the unsupported CPU (Bug Note:34117) - now I´m running GemStone/S on Athlon 64/X2 with SSD2 support.
I tried out on P3 866, Celeron 833 and AMD Athlon 1700+ - they all have no SSD2 support.
So now I have to swap my server with a new CPU - and then all will be fine ..
I´m so happy :)
Kind regards
Mark