I have worked with several Dell Latitude E6440's, and they exhibit the same problem: The USB 3.0 ports function at USB 2.0 speeds. I have followed your Dell Latitude E6440 Windows 7 Driver Install Order to a T, and I've tried both the latest USB 3.0 driver from Intel's website (which, for the record, I should be able to use with no problems) as well as your horribly outdated one from the Latitude E6440's product support page.
The problem persists. If I plug a USB 3.0 device into the USB 3.0 ports, I will receive a balloon that says "This device can perform faster," informing me to plug the device into a USB 3.0 port. The device is plugged into a USB 3.0 port.