Lol. Don't know why it would! No. It was just frozen mango.
Look. Here's a cooking board thread from 2001 where someone else thinks their frozen mango tasted fishy.
http://community.cookinglight.com/archive/index.php/t-7191.html
And another one from a different message board.
http://forums.anandtech.com/showthread.php?t=187855
I feel comforted that at least I'm not the only one in cyberspace that thinks so.