BETA #2 is now available HERE.
This is mostly to fix RTL language display, which had multiple issues, and to update additional translations.
Now, with regards to the issue reported by TheHive, this seems to be a Windows bug
From what I can see, if you create a toolbar that contains multiple buttons, then Windows will not forward the tooltip notification messages (TTN_GETDISPINFO) to each individual button, unless the Windows has the focus. On the other hand, it does forward the global tooltip notification message for the whole toolbar, regardless of focus. In other words, if you try to attach a tooltip to the whole toolbar it works. But if you try to attach tooltips to individual buttons it doesn't. And alas, Windows doesn't provide a way to, say, add a call to find on which button the mouse pointer is hovering if you use the global message...
Considering that it makes no sense to forward one and not the other, it's pretty clear that what we are being confronted with here is a Windows UI bug...
The one workaround I can see for this would be to split our 4-button toolbar into 4 individual ones, each with a single button, since we then could set global individual tooltips for each one, which would display regardless of window focus. But I have to say it's a bit of a pain in the ass to have do so just to display 4 tooltips that people will be able to see as long as the Window has the focus, so I'm not sure I'm going to bother...