Dell PowerEdge 2950 II - Unsupported cpu combination System halted

I bought two new processors for my PowerEdge 2950 II and the place get the error below:

Unsupported cpu combination

System halted

The processors are the model Xeon E5440, socket LGA771.

The BIOS version is 2.4.3.

Using my Service Tag on the Dell site is available an update for my BIOS in version 2.7.0.

I wonder if this version really adds support to my processor.

Any risk doing this update?

Thanks,

Rodrigo Ventura.