http://lmgtfy.com/?q=site%3Abitcointalk.org+%22bitcoin+trader%22
Google is better for general searches like that. I usually only use the forum search for posts by a specific person or in a particular board.
I totally agree. You can use the parameter site:bitcointalk.org for searching contents in this forum. For eg:- Bitcoin Trader site:bitcointalk.org , by searching like this, you can get posts/threads which contains Bitcoin Trader in it.
It would be better if you search more specifically, otherwise you may get a lot of links which will make it a bit harder to find. If you know approx. time when the thread was made, you can click 'Search tools' and then click 'Anytime' and change it to Past day or month etc... according to the time.
~~MZ~~