"Open messages in: A new message window" preference not respected

[yummysoup]

Even though I set the preference:
Tools > Options > Advanced > Reading & Display > Reading > Open Message In: (*) A new message window

Whenever a double-click a message in a list, a new tab is opened. If I disable the Conversations Add-on, messages open in a new window as I've set.

Thunderbird conversations: 2.0.6
Thunderbird: 5.0
Windows 7

[protz]

Hi,

I do not plan on honoring that preference.

[yummysoup]

To clarify, I'm not asking for Conversations UI in a new window.

Instead, I'd like double-clicking a message in a list to perform the same action as right-clicking the message and choosing "Open Message in a New Window"

(I use the Conversations UI through the Message Pane but would often like to open messages in new windows, even if they have the "classic" UI (i.e., not Conversations))