Ahh, remember? When I introduced these from forever ago? Yeah, me too. Hehe. Okay well now I'm back to break down the little minor differences.
Bisexuality is limited to two gender identities. If more, you'd be polysexual.
Pansexuality is not limited in gender. Anyone of any identity. Anyone male, female, or anyone between the two ends of the spectrum. Or someone who's agender, and isn't on the spectrum at all. They count too.
Examples of bisexuality:
"The love of my life is a man, but I'm still attracted to females."
Pansexuality:
"I'm attracted to men with penises, women with penises, men with vaginas, women with vaginas, people with vaginas, people with penises, Gender fluid people, intersex, agender, basically infinite. You get the idea."
I hope this cleared up any confusion between the two. Please vote and comment :) next entry is on the difference between gynephilic and androphilic.