Wanted - A 3rd party tabbed-rooms chat to integrate with drupal or a "real" chat drupal module

Hi guys,

I have spent literally a few days looking for what I need and did not get a reasonable solution, so I asking for help.

I need a chatting capability which will give all of the following features, most are usually found in traditional chat systems. These are:
1. Anonymous users can take part in the chat
2. A main entrance room ("lobby")
3. A list on a sidebar with all chatters
4. User can open a private chat with another user by clicking her name (the name in the list and/or her name inside the lobby room on the line where she said something)
5. The private chat will be in the same window but in another tab (MDI style, just as multi-tabs browsers)
6. The addressee will see clearly that he has a new message (both in a new conversation or in an existing one, e.g., colored tab).

Here is a list of what I have tried so far, each accompanied with a reason why it was not good for me.
Chat Room - Naturally this is where I have started and would like to find my solution, but this is not the case. Lacks features 3, 4 and 5
phpfreechat - Full of bugs, works only sometimes (could not find the criteria when).
Instant messenger - Very fast, but it is not clear whom you are talking to. Lacks features 4 and 5.

Other modules which I have tried, though not intended to be called a chat, all are wrappers for 3rd party widgets which provide facebook-like floating toolbar. They are:
CHAT Users and Design Integrated (bowob) - Enables drupal users to talk between them. A problem with non-latin characters in users' names, though.
Wibiya - I could not make it run (issue)
Meebo - Does not let drupal users to talk between them, only the user's facebook friends (issue)

So, that's about it. Any ideas, thoughts, etc. will be really appreciated.

Thanks!