Won't work always, sometimes requires Enter key, but sometimes works immediately after release mouse button.
It behaves that way if dialog is under cursor when mouse button is released, I'll check what can be done about that.
Tab order in the popup window is different than real tab order: ascending next tabs, but descending previous ones.
It's intentional, I'm planning to add option to select mode for ordering.
Sometimes creates a new blank tab after the last tab, immediately after release mouse button. Probably just after cold start with session restore.
Maybe gesture to add new tab gets triggered accidentally?
In Opera, I'm using tab scroll gesture in hidden mode, but didn't find this setting in Otter yet.
It's planned too.