I was trying to find the tech debate thread by searching, "amd" through posts by M1_Mercenary and got nothing. From this I'm assuming queries are case sensitive. It's not really a big issue; however, it's kind of annoying. >.<
Nope it's a limit in XenForo, you can't do searches with 3 or less characters without modifying the source and the MySQL config, it rapes the database.