I have an m2616 and an m2008 on my desk. They both have the same PDN and rollover. I have the 2008 so that when i am on hold with AT&T for hours i can still use the other phone. How come, if I am on the 2008 and i stat that TN it shows BUSY, but so does the M2616 TN? If the M2616 handset is in the cradle why does that TN show as BUSY too? thank you.