Can user-agents be listed together, followed by their common rules like so in a robots.txt?
User-agent: Googlebot User-agent: ia_archiver #Alexa User-agent: BingPreview #Microsoft User-agent: bingbot #Microsoft User-agent: MSNBot #Microsoft User-agent: Slurp #Yahoo User-agent: Ask Jeeves/Teoma #Ask Disallow: /adm30_buds/
user-agent: *followed by the disallow? Is the list of "allowed" user-agents longer than the list that you want to disallow?