Most of the time, I can drag IE9 tabs to remove to a new window, or rearrange their order in the current window. Seemingly randomly, the tabs no longer are moveable. That is, they can no longer be dragged out of, or rearranged within, the current window. You can still create new tabs, and close existing tabs.
- Closing IE9 completely does not fix the behavior.
- Logging out of Windows current user and back in DOES fix the behavior.
Then either a few hours, days, or weeks later, it happens again.
9.0.8112.16421 64-Bit Edition Update Versions: 9.0.5 Windows 7 Premium fully patch current
Edit: After a time, the tabs being movable recovers on its own, at least this once.