Can add a sql server 2012 node to a sql server 2008 R2 cluster?

Hi,

Can i add a sql server 2012 node to a sql server 2008 R2 cluster?

I got the "yes" answer from Microsoft SQL Server Sales, but when i wanted to add the sql server 2012 node to an existing sql server 2008 r2 cluster,the setup can't find the sql server 2008 R2 cluster instance. 

So i doubt whether this is true or not feasible, many thanks.