I have a 3100-40 which has a 4Gb drive as a boot drive.  The model 40 is
SUPPOSED to be the same as the 30, but different case, expansion, etc.
The model 30 memory certainly works in the 40.  I seem to recall it is
more an issue of age of firmware.  I just asked a computer parts place
I do business with about my model 30 and they said a 4Gb drive is the
biggest that will work in it.  Didn't try it though, just went to the
model 40 (needed the space for more drives).
Joe Heck