Program is not recognizing administrator logon

I am trying to enter a registration code required for activation of a third
party program (SONAR PRODUCER 6, www.cakewalk.com) which I use under XP Pro,
but now wish to activate on SAME computer under Windows Vista x64.

There is a field in which to enter this code which remains locked with the
message that I am ''not logged as the administrator'', but I am.

I have closed all other profiles to make sure none is interfering, and just
logged as administrator, but the problem remain.

I am awaiting reply from the Cakewalk, but in the case there might be an
explanation here, I try.

Thanks,

Rob