Headers of same level after each other causes content loss

I'm using the latest trunk (rev. 127).

When using two or more headers of the same level after
each other, all content starting from the second one
gets removed.

Suppose you have the following source:

<header level="1">Heading 1</header>
This is part 1 of the test article.

<header level="2">Heading 1.1</header>
This is part 1.1 of the test article.

<header level="2">Heading 1.2</header>
This is part 1.2 of the test article.

All what's left after storing the draft while the
editor is enabled:

<header level="1">Heading 1</header>
This is part 1 of the test article.

<header level="2">Heading 1.1</header>
This is part 1.1 of the test article.

Best regards

K.