OK, I seem to have found out at least one part as to why my material wa so extremely memory-active: NEVER EVER MIX DIFFERENT MAPPING MODES. I mapped the bark material to be "object-cylindrical" while the moss material and some of its functions were "object-standard". I started setting al functions and all mappings to "object-cylindrical" and suddenly the material began to render a bit faster. It still took about 7 or 8 minutes to render it's final preview. And it is only that final preview window in the texture editor, that slows everything down. If I hit the "ZOOM" buttan, the zoom renders in about 15 seconds - an acceptable time for this material. But the little preview won't render in less then 8 minutes. Strange indeed. Maybe the material-settings are just to complicated? Joerg