Unexpected error when creating SEP 12.1.2 SQL Database

I'm creating a new SEP 12 environment:

1 SQL server - Windows 2008 R2 w/ SQL 2012

2 SEPM's - Windows 2008 R2

The SEPM part of the installation works until I get to the database creation stage - I enter the details for Step One - it allows me to connect to the database

I enter the details for Step Two, as soon as I click next I'm given an 'Unexpected Error'

I've tried this on both SEPM's with the same result - I've submitted the troubleshooting logs to Symantec support with nothing obvious showing in those.

Any thoughts/ideas?

Cheers,

Mike