due to activity falling off of my surfaces, i've been toying w/ 3dVol2Surf

i'm having trouble, so let me show you how i called it and what resulted

3dVol2Surf \
-spec subject_rh.spec \
-surf_A rh.smoothwm \
-sv subject_SurfVol+orig \
-grid_parent subject_SurfVol+orig \
-use_norms \
-norm_len 2.5 \
-map_func ave \
-out_niml rh.Vol2Surf_test

i also tried

3dVol2Surf \
-spec subject_rh.spec \
-surf_A rh.smoothwm \
-surf_B rh.pial \
-sv subject_SurfVol+orig \
-grid_parent subject_SurfVol+orig \
-map_func ave \
-out_niml rh.Vol2Surf_test

3dVol2Surf completes fine both ways, outputting the rh.Vol2Surf_test surface. However, when i run this through @SUMA_Make_Spec_FS, i hit a snag. It does count rh.Vol2Surf_test as a surface, but gets hung up when making the asc files---printing out "freadFloat: fread failed" over and over.

The reason i use 3dVol2Surf in the first place is that i have activity that is neither bordering the white matter segmentation, nor is contiguous with activity that is bordering the white matter segmentation. Thus, it is missed.

A question: is my usage of 3dVol2Surf inappropriate given my needs?
Another: how does the process differ if only specify surf_A + normal vectors rather than specifying surf_A + surf_B w/o the normals? which way might be better given what i'm trying to do?