can't add spamicide to a webform (displayed in block)

I am using the Simplenews module and the form appears on my pages in a block.
Appearing in the block is the option to add spamicide protection "Add Spamicide protection to this form." which links to the following URL
admin/config/spamicide/spamicide_form/add/simplenews_block_form_2
Yet the simplenews_block_form_2 never appears in the list of field IDs and
the display message "Add Spamicide protection to this form." remains visible and persistant inside the Simplenews block on my pages
Is there anything I can try to remedy this issue?
Thanks