I believe that the code you are looking for is in ubb_lib.cgi, search for something along the lines of "message to smilie-fy" and underneath will be a list of smilies and their relavent shortcuts (e.g. :D), I think if you deleted the whole section on smilies they should be gone. There also may be some Graemlin code in ubb_lib_posting.cgi, remember to make back-ups before you start to modify the files!
