UBB.threads PHP Forum Software Community Forums UBB.threads Version 7/8 Support Very strange login failure

Here's something strange. When I run the following command, I get a return for my account but not for his.

select * from xxx_USERS where USER_LOGIN_NAME='mine'

select * from xxx_USERS where USER_LOGIN_NAME='his'

(I've munged the three letter prefix that I use and replaced the actual user login names with mine and his.)

That indicates that there is something wrong with his account but what?