thanks for the reply alan. i would have tried your suggestion if i hadn't found out what i did wrong.
after i posted my message, i had another look at it and i think i know what the problem is. or at least i got it fixed.
there is a command that turnes raytracing on: "-ert 1". i thought i'd be sure and use that command to make sure my scene got raytraced. well, it turns out that maya gets confused by this command or something, coz when i didn't give that command it just rendered my scene with the lights i set up myself. so no default lights stuff.

all i'm gonna do from now on, is set up everything as i want it in my render globals. in the dos window i then only give the path and the filename in the render command and it works fine.

tiz