Trinity setup wont post with 2133MHz RAM set

[Centauri]

So I bought 2133 RAM because I know how well these APUs can gorge on memory bandwidth, but when I try to set it for 2133MHz (which the EFI supports) the machine wont even post. 1866 runs fine though.

Any idea what I could be doing wrong? Do I need to increase voltage to the Northbridge?

http://www.newegg.com/Product/Produc...82E16813157331

Any insights would be appreciated.
Thanks peeps.