P.S.:I executed the following sequence to achieve the first level analysis with a correct registration.
preproc-sess -s session_id -fsd bold -sliceorder siemens -surface fsaverage lhrh -mni305 -fwhm 0 -per-run
register-sess -s session_id -fsd bold -per-run -init-header
preproc-sess -s session_id -fsd bold -sliceorder siemens -surface fsaverage lhrh -mni305 -fwhm 0 -per-run -noreg -regfile session_id/bold/001/register.dof6.dat -force
selxavg3-sess -s session_id -analysis stim.sm0.lh -no-preproc
As far as I can see this is the right procedure. Do you agree or is there another or simpler way to correct the registration and proceed with a first level analysis?