I don't find that to be the case. 1.4.2 firmware.
Alice calls Bob (D50).
Bob answers the call.
Alice and Bob converse.
Bob presses the Hold button to place Alice on hold.
Alice hears hold music.
Charlie calls Bob.
Bob has a new call handle appear on his screen below the call handle with Alice.
Bob presses the down arrow on the keypad.
Bob presses the Answer soft key to answer the call.
Charlie and Bob converse.
Bob presses the Hold button to place Charlie on hold.
Charlie hears hold music.
Bob's phone highlights the call handle with Charlie.
Bob presses the Conference hard key on his phone.
The phone's status bar now says "Conference to..."
Bob presses the up arrow to highlight Alice's call handle.
Bob presses the Conference hard key again.
Alice and Charlie are taken off of hold and they're all involved, with Bob, in a local 3-way conference.
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