ctrl+W does not work in firefox

[Tapas Mishra]

While watching this video
http://www.youtube.com/v/znxQOPFg2mo

Ctrl+W did not worked on my laptop.
Dell Inspiron 1440.


Firefox 3.6.8

Extensions
       Google Toolbar for Firefox 7.1.20100830L
       TheFreeDictionarycom Community Toolbar 3.1.0.12
       Conduit Engine 3.1.0.12

Theme

       Default 3.6.8

Plugins
       Windows Media Player Plug-in 10 (compatible;Totem)
       VLC Multimedia Plugin(compatible Totem 2.30.2)
       Shockwave Flash (10.1 r82)
       QuickTime Plug-in 7.6.6



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Tapas