Interesting do you remember who/where?
Well I'm having trouble finding it. Perhaps I read it at the same place you did. I searched the first 1800 posts of this thread then decided that I didn't want to spend my afternoon doing that so let me just say that I had the thought at the time I read it that it was similar to the Virgin Airways flight from SF to London that was cancelled. Below are links to the various posts in this thread about suspicious airplane activity (excluding NW 387):
http://www.freerepublic.com/focus/f-news/1183755/posts?page=214#214
Romanian passports
http://www.freerepublic.com/focus/f-news/1183924/posts
http://www.freerepublic.com/focus/f-news/1183755/posts?page=766#766
http://www.freerepublic.com/focus/f-news/1183755/posts?page=1001#1001
Rumor of missing BA flight SF to London
http://www.freerepublic.com/focus/f-news/1183755/posts?page=1255#1255
Virgin Air SF to London