is_year bug with static front page

Examples:

../blog/ still works showing all posts.
../blog/2006/08/ works showing monthly posts.
../blog/2008/ does not work as it should work anymore:

Since upgrading from 2.7.1 to 2.8.X I recognize that “if (is_year())” does not start with the chosen yearly archive anymore but with most recent blog posts followed by the yearly archive posts later on page 2. If you run a pagebar you can see that on the first page of yearly archives it rewinds all existing posts like on the start page of the blog.

Does anyone have the same problem or an idea how to fix it?
Blogs without a static front page seem to work as usual.