E7450 Undocked keyboard issues

Hello, I'm checking to see if anyone has experienced this behavior before.  We are a mostly Dell shop with various models in operation.  On our latest models the Latitude E7450, we have a couple of employees with this strange issue.

Most of the time, the laptops are docked in the standard E-Dock port replicators and usually 2 monitors attached.  Let's say an employee undocks their laptop and goes to a meeting.  When they open the laptop to use the internal keyboard and trackpad intermittently they keyboard will appear not work.  The trackpad will work to move the pointer open documents or websites, but when the keyboard is used no characters will show on the screen.  If the trackpad is touched, then the characters appear on the screen like they were buffered and the system was waiting for some kind of input.  This happens for any key, we can push the "Windows" key and the start menu won't come up until you move the mouse, then the start menu opens.

We've tried updating:

Latest BIOS

Keyboard/Trackpad Drivers

Video Drivers

Finally, we re-imaged one with our corporate image, but this did not fix the issue and the employee came back a few days later with the same issue.  Has anyone experienced this?

Dell Latitude E7450

Windows 7 Enterprise x64