I tried using the gltsym option, but got the following error message.

Below is also the 3dDeconvolve script I am using. I set it up according to the AFNI how-to on creating optimal timing sequences.

If someone has insight as to what is causing this error, please let me know.

++ 3dDeconvolve: AFNI version=AFNI_2008_07_18_1710 (Apr 15 2009) [32-bit]
++ Authored by: B. Douglas Ward, et al.
++ using NT=257 time points for -nodata
*+ WARNING: Input polort=1; Longest run=257.0 s; Recommended minimum polort=2
** ERROR: -gltsym: can't match symbolic name ''
** ERROR: -gltsym: can't match symbolic name ''
** ERROR: -gltsym: can't match symbolic name ''
** ERROR: -gltsym: can't match symbolic name ''
** ERROR: -gltsym: can't match symbolic name ''
------------------------------------------------------------
GLT matrix from 'SYM: +N111 + N110 + N101 + N100 -N011 -N010 -N001 -N000 + V111 + V110 +V101 +V100 -V011 -V010 -V001 -V000':
0 0 1 1 1 1 -1 -1 -1 -1 1 1 1 1 -1 -1 -1 -1

** ERROR: -gltsym errors immediately above from file 'SYM: +N111 + N110 + N101 + N100 -N011 -N010 -N001 -N000 + V111 + V110 +V101 +V100 -V011 -V010 -V001 -V000'
** FATAL ERROR: Can't continue after the above -gltsym problems!
** Program compile date = Apr 15 2009
Invalid null command.

Script:
#!/bin/tcsh

set stim = 16 \

foreach iter (`count -digits 3 1 100`)

3dDeconvolve \
-nodata \
-nfirst 4 \
-nlast 256 \
-polort 1 \
-num_stimts ${stim} \
-stim_file 1 wav.1D/"wav.hrf.${iter}.1.1D" \
-stim_label 1 "N111" \
-stim_file 2 wav.1D/"wav.hrf.${iter}.2.1D" \
-stim_label 2 "N110" \
-stim_file 3 wav.1D/"wav.hrf.${iter}.3.1D" \
-stim_label 3 "N101" \
-stim_file 4 wav.1D/"wav.hrf.${iter}.4.1D" \
-stim_label 4 "N100" \
-stim_file 5 wav.1D/"wav.hrf.${iter}.5.1D" \
-stim_label 5 "N011" \
-stim_file 6 wav.1D/"wav.hrf.${iter}.6.1D" \
-stim_label 6 "N010" \
-stim_file 7 wav.1D/"wav.hrf.${iter}.7.1D" \
-stim_label 7 "N001" \
-stim_file 8 wav.1D/"wav.hrf.${iter}.8.1D" \
-stim_label 8 "N000" \
-stim_file 9 wav.1D/"wav.hrf.${iter}.9.1D" \
-stim_label 9 "V111" \
-stim_file 10 wav.1D/"wav.hrf.${iter}.10.1D" \
-stim_label 10 "V110" \
-stim_file 11 wav.1D/"wav.hrf.${iter}.11.1D" \
-stim_label 11 "V101" \
-stim_file 12 wav.1D/"wav.hrf.${iter}.12.1D" \
-stim_label 12 "V100" \
-stim_file 13 wav.1D/"wav.hrf.${iter}.13.1D" \
-stim_label 13 "V011" \
-stim_file 14 wav.1D/"wav.hrf.${iter}.14.1D" \
-stim_label 14 "V010" \
-stim_file 15 wav.1D/"wav.hrf.${iter}.15.1D" \
-stim_label 15 "V001" \
-stim_file 16 wav.1D/"wav.hrf.${iter}.16.1D" \
-stim_label 16 "V000" \
-gltsym 'SYM: +N111 + N110 + N101 + N100 -N011 -N010 -N001 -N000 + V111 + V110 +V101 +V100 -V011 -V010 -V001 -V000' -glt_label 1 'HIconst-LOconst' \
#-glt 1 contrasts/contrast_hivslo_const \
#-glt 1 contrasts/contrast_hivslo_sensmo \
#-glt 1 contrasts/contrast_hivslo_freq \

> 3dD.nodata.${iter}

end