When people say "USB 2.0" there are actually two very different variations.
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Full-Speed USB, which is essentially USB 1.1 relabelled and called "USB 2.0". Full Speed USB is only 12Mbits/second.
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Hi-Speed USB mode is capable of a much faster 480Mbits/second.
More information here:
http://www.everythingusb.com/usb2/faq.htm
Hope that helps.