I think you need to add quotes to all filenames for the spd command lines on windows:
Tue Oct 30 16:37:43 CET 2007 Preprocessor mode is Off line
Tue Oct 30 16:40:15 CET 2007 cmd /C C:\Documents and Settings\WRIGHT\Desktop\fable.preprocessor\plugins\spd_1.2.0\bin\win32\spd.exe
cor_ext=cor src_ext=edf dark_file=G:\test_spd\dark_60s.edf dark_const=0
inp_const=0 inp_factor=1 inp_exp=1 save_dark=2 flood_file=G:\test_spd\Rh_flood.edf
distortion_file=G:\test_spd\spatial2k.spline do_distortion=2 flat_distortion=1
pass=1 G:\test_spd/17a_ins0006.edf G:\test_spd/17a_ins0000.edf G:\test_spd/17a_ins0001.edf
G:\test_spd/17a_ins0002.edf G:\test_spd/17a_ins0003.edf G:\test_spd/17a_ins0004.edf
G:\test_spd/17a_ins0005.edf
Tue Oct 30 16:40:15 CET 2007 'C:\Documents' is not recognized as an internal or external command,
It works if I move the fable.preprocessor directory to c:\fable.preprocessor then it works
A lot of people work in "C:\my documents" etc...