This thread says I should be getting a message on stderr if I attempt to bind two sockets to the same port. I don't (and have tested it's not an issue with my IDE by spewing my own text to stderr, which displays fine).
Additionally, the second (illegal) call to Bind() returns true. Surely it should return false if this is not allowed?
I'm on SFML 1.6, Win7 x64 if that helps.