I have not yet done an 'upgrade' from 7.09 to 7.1 yet (I built from new install). There seems to be a document on wiki that explains you can upgrade directly from 7.09 to 7.1.
But, When you download the 'Cumulative' package, I can see files for 7.0.9>7.1B1 and 7.1B1>7.1B2, and 7.1B2 > 7.1
So does this mean you have to go through B1 and B2 before you can reach the 'final' 7.1 upgrade?