Keyboard, mouse, and headset keep dropping drivers

Hi I am Josh and I work in the IT department for a call center and we use a soft phone to communicate with our customers we just currently upgraded all of our pc's to windows 7 64 bit lenovo 3484 model machines with usb mouse and keyboard that came with the machines and we are using vxix100 and x200 usb plug and play adapters for headsets. Everything was running smoothly until lately I keep getting multiple reports that the agents loose sound in their headset and then their keyboard and mouse quit working. I have tried everything windows updates different adapters searching the net so I decided to make a post here is what I see in event view when it drops keyboards and mouse. 

I have read a Microsoft forum and it said this happens on start up but it has been happening on our agents when they are in a middle of a call. Any and all help would be appreciated