Making a new call with CSTA after a hold

[dcoup]

I have three extensions (103, 110, and 111) managed by a Panasonic NCP PBX. I can manually do this sequence, and it works:
[ol 1]
[li]Dial 110 from extension 103.[/li]
[li]Answer at 110.[/li]
[li]Place the call on hold at 103.[/li]
[li]Dial 111 from extension 103.[/li]
[li]Answer at 111.[/li]
[/ol]

But if I try to do what I think is the equivalent sequence with CSTA messages, it doesn't work:
[ol 1]
[li]Send a Make Call message to have 103 call 110.[/li]
[li]Send an Answer Call message to answer the call.[/li]
[li]Send a Hold Call message to place the call on hold.[/li]
[li]Send a Make Call message to have 103 call 111. This results in the PBX returning an invalidObjectState error.[/li]
[/ol]

Anybody with some CSTA savvy know what I might be doing wrong?