Fingers crossed it works for you
Remeber that if you change the quality settings in the hardware render options then for some reason it will default the high quality lighting option back on.

Another thing for the future is that in Maya 2008 quote:
'Additionally, particle types previously supported
only in the Maya Hardware renderer can now be
rendered in mental ray, eliminating the need to
combine outputs from multiple renderers.'

So there wont be as much reliance on the hardware installed
That can only be a good thing though I dont know how it will affect rendering times

Si