Tabs are a tricky business

Several applications with tabbed interfaces critiqued ...

"... Terrible. I always think I’m supposed to click the hanging tab to close the current tab instead of create a new one. And when multiple tabs are open, I can’t close an inactive tab without first making it active. Select it to see the X, then click it. Why not show the X when I roll over the inactive tab?"    (Continued via rhjr.net)    [Usability Resources]

IE7 Tabbed Interface