unexpected document window switch

When several views (documents) are open, opening and closing Log view switches to the 1st document.
Steps to reproduce:
1) Open several documents of any kind - sequence view, workflow designer, whatever.
2) Activate any document except the #1 (as numbered in Window menu).
3) Click on the Log button at bottom toolbar, Log view is opened.
4) Click on the Log button again, Log view is closed and suddenly the document #1 is activated.
This behavior does not depend on window layout.