The Notation Composer and Musician version 1.9.15C beta release extends the beta period until December 19, 2006. You can download it from
www.notation.com/MidiNotateBetaRelease.htm
This fixes a problem that 1.9.15B did not correctly extend the beta period.
It will not be necessary for you to first uninstall 1.9.15B or any other prior beta release. You can install 1.9.15C "on top" of 1.9.15B or any 1.9.x beta release.
Cheers
-- Mark