I have just gotten an E7240 computer and have noticed that the USB ports on the back of my computer are disabled when the computer is docked which is a very unfortunate feature of this new computer model. It seems there are many people posting complaints about this feature on the internet. It basically takes a computer that has 3 USB ports and makes two of them rather useless. It is very useful if a USB receiver for keyboard and mouse can be plugged in to the back of the computer so that the mouse can be used easily when docked, but also when the computer is taken off the dock to go to a meeting room. This then leaves the side USB port available for devices such as wireless projectors when in the meeting room. Although this computer was designed to behave this way, I think that most users would agree that this is a critical issue that needs to be seriously considered and fixed by Dell as soon as possible assuming that there is not already a work around available.
I'm having the same problem. It certainly seems to be a common problem from what I've read elsewhere online. Dell - any response on this? Alongside the other problems with USB disconnects when redocking the E7240, there seem to be quite a few related issues!
This is the biggest design failure I've seen in a long time. It ranks right up there with Lenovo moving "Fn" to the lower left position on the keyboard where "Ctrl" has been for 30 years. Having an E5450 with essentially one persistent USB port is a daily nuisance for anyone in a business environment who moves from their desk to multiple meetings daily or even between home and work where they may need devices such as a wireless mouse, wireless head-set,and a USB hard drive. HUGE FAIL for business users.