Wrong chat tab focus (ms win)

The tab that is active is not always the first one. The one that is open is the last used one.
It is also the same behavior when the window is active and in front, there I think this is OK, to not disrupt you from an ongoing conversation.
But it may probably make sense when the window is in the background to activate the tab where the last message was received. Sander, any comments?

True, if the chat window is open and in foreground then you should just mark the tab where new message appear. Also, marking it just with number of messages is not very noticatble. Color change is alot better.
But when window is closed then open it on the right tab.
I am not sure what to do when it is open and unfocused, becase it might be unfocused but fully visible and someone can monitor messages in a tab. Maybe it is better to not switch the tab in this case and change the colors of tabs where there are new messages.

I think automatically switching the tabs can be annoying, even if it is only done when the window is in background. Consider this scenario:
1) You are in a whiteboard session with a contact.
2) You are in a chat session with the same contact.
3) The chat window is positioned next to the whiteboard window so that can can see the incoming messages of this contact whilst editing.
4) The whiteboard window is active as you are editing its content. Hence, the chat window is in the background, but you still can see it as it is positioned next to the whiteboard window.
5) Another contact sends a message, causing the conversation with the contact of the whiteboard session to become hidden in another tab. As a result you cannot anymore read the instructions that your whiteboard contact gave you (e.g. "draw a triangle above the circle"). == annoying
6) Both the whiteboard contact and the other contact start typing multiple messages. This continuous switching causes flicker that distracts you from your whiteboard work. == very annoying + bad for productivity

So, I think the requested feature only can be implemented for a *minimized* chat window.

I agreen. Switching to the right tab must be done only when a window is totally hidden.

But also, a better notification on tabs where new messages are must be done.