To work around this problem, use a standard keyboard to enter administrator credentials.
This problem occurs because the Tablet PC Input Panel always runs in the security context of a standard user account. To block malicious software from acquiring elevated administrator rights and permissions, Windows Vista only lets trusted processes run when you try to start an application that requires administrator credentials. Trusted processes are processes that run in the security context of an administrator account.
(Posted by an unknown user) Rating
they probably knew that was an obvious option-the question still remains unanswered...