POWER5 to POWER5+ Upgrade

["Dean Boyle" <dean_boyle@xxxxxxxxxxx>]

Hi,
Has anyone been involved in an i5 upgrade from a POWER5 to a POWER5+ box. 
In my case, the  upgrade only involves a new CEC (system unit)...all 
existing expansions will attach to the target configuration. I'm running 
V5R3 and I know that I have to permanently apply the latest cumulative PTF 
package to bring the LIC and OS levels to the latest resave version.  I will 
also have to upgrade the old version of HMC (V4) to at least 5.2 but does 
anyone know if I also have to upgrade the firmware before I upgrade the CEC? 
The FSP will obviously be replaced as part of the CEC swap and will come 
with a new firmware version but I'm sure I've read somewhere that the POWER5 
source box still has to be upgraded to a recent firmware level BEFORE the 
upgrade to POWER5+?  I'm not sure why because the firmware resides in the 
FSP.  Anyone done this?
Any help appreciated.