The :after? tag doesn't appear to apply to input elements, buttons, text_fields, and frames.

As an example, the following fails to find the relevant text_field:

   require 'watir'
   ie=Watir::IE.start("http://news.bbc.co.uk/")
   ie.text_field(:after?, ie.button(:id, "toolbar-search-button")).flash

Whereas, these individual elements CAN be found:
   ie.button(:id, "toolbar-search-button").flash
or an alternative way of finding the text_field:
   ie.text_field(:id, "toolbar-search-input").flash

( From the following mailing list discussion: http://rubyforge.org/pipermail/wtr-general/2007-July/011747.html )