What's the difference between UA awards, and Star Alliance awards that are redeemed with UA MP miles?

In other words, the numbers here (accessed from www.united.com/awardchanges) are different from the ones here (accessed from http://www.united.com/page/article/0,6722,50042,00.html).

For what I'm interested in, NZ, the UA award is pricier than the *A award...