Lol... how did u manage to test this ?? You should seriously be in Testing if you are not ! .. No idea why, may be he as has extra spaces / blank characters at the end .. possibility ??
chances of whatever super-man has said is greater... but there are two more chances: 1) server error 2) some special characters which are of different encoding but look same.. (not just similar)
I have been in software modules testing + application building for few months - half a decade ago. On hindsight - sorry for the utterly non-informative title of the thread.