Rated 1 out of 5 stars

Doesn't seem to change a thing. My replies still want to go out on different accounts. Using Thunderbird 31.1.0
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The selection tab is set to use the default identity of the account, and the box is checked for "When replying a message". If I click other accounts, it remains checked. If I am the sole recipient of a message in my default email account, it is responding with a different account. Similarly on the Detection tab, the box is checked and shows up as such for every account.
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What I just noticed is the replies that switch accounts don't show a recipient (bcc) but I only correspond (daily) with this person on only the default account. The end result is exactly the same with or without this addon; bcc emails switch accounts, named ones do not. Hope this helps you find a fix!

This review is for a previous version of the add-on (1.4.3). 

Did you open the options of the addon and enable the 'attempt to find and use an identity that appear in its recipient list' checkbox for each of your mail accounts? Furthermore on the detection tab you can enable/disable detection for each identity individually.
If the addon still doesn't work please disable all your other addons one by one to see if these are interfering.