Hello Kombrig,
That explains the problem. You have been seeing a bug that was in version 1.1.7 that was fixed in Composer 2.0, which was released on December 16, two weeks ago.
Since you purchased Composer 1.1 after February 1, 2006, you are entitled to a free upgrade to Composer 2.0 at:
http://www.notation.com/FreeUpdateToNotation20.php
Composer 2.0 will fix the problem you've been seeing.
And, Composer 2.0 is overall a major improvement over 1.1.
Cheers
-- Mark