Answer second call or make a call when busy

[jdackert]

I may have the same problem. I can't answer a second inbound call if a line is active.
I can put the first call on hold, but pressing the flashing Line2 key doesn't answer the incoming call, it gives me dial tone.
I also can't hang up on line1 and answer line 2, just get dial tone. If the phone is idle when when line 2 is called I can answer line 2.
T-28 running 2.71.0.140