CX 600 bug

I was told of this recent bug by a fellow consultant. Hope it helps others. Polycom CX600 (Lync Phone Edition release 4.0.7577.250 (CU2)) and Lync client. USB connection between IP phone and Client. - User is in a call on the phone - 2nd Call comes in - If second call has same phone number as previous caller or comes in with suppressed phone number, secondary call will disrupt the first call and becomes active/connected immediately. - If the USB connector has been pulled, this error does not show up