This message is common on Vista and Win 7 systems, when reading devices that have been used on prior versions of Windows, or which were unexpectedly removed at some point. This error
does not mean your file system is corrupt, it just means it was unexpectedly removed at some point.
Modern versions of Windows (7 and Vista) constantly flush data to removable devices. This means that pulling the plug without "ejecting" them should not cause data corruption. Microsoft knows this is how people use their devices, so they "fixed" the behavior.
You can read an explanation of what the message means, and how to fix it, here:
http://www.futureofrealestatetechnol...other-devices/
This doesn't mean you can't or shouldn't eject your devices before unplugging them, but don't panic if you forget, it's probably harmless.