Ohhhh, just a reason more to get another one...;) Thanks for the hint!
In this case I only had MorphOS Storage and moph.zone opened but maybe it is also due to the graphics card...?
AmigaOne X5000 @ 2GHz / 4GB RAM / Radeon X1650 / AmigaOS 4.1 Final Edition / MorphOS 3.19
Amiga1200 / Blizzard 1230 IV PiStorm32-lite / 128 MB RAM / AmigaOS 3.9
