Dot Biz doesn't resolve to punycode in Firefox

[Olney]

I was just looking at a domain that Burns posted in Appraisal for a Spanish dot Biz.
I noticed that they don't resolve to punycode.
The extensions I find that resolve to punycode in FireFox are
.com
.net
.cc
.tv

I'm assuming that .info resolves to Unicode in firefox huh?
I'm using FireFox 2 no difference in my dot coms.