Over 100 cases have been reported to the FDA involving the use of Tamiflu and the development of hallucinations, delerium and other unusual behavior mainly in Japanese children. From the Chicago Tribune article "Health officials have been sensitive about taking any action that might dissuade people from taking Tamiflu, since the drug could play an important role in an outbreak of bird flu."
Read more about it in the Chicago Tribune and FDA websites…here are the links: