Patch level for upgrading to 2007A

Can you upgrade directly to 2007A SP00 PL45?

A recent thread discussed upgrading to B1 2007A. In the thread, it was said that you must upgrade to 2007A SP00 PL30 then patch to any higher level.

It is not my understanding. I think that you only have to go to PL30 first if you are doing a full re-install of B1. If you are doing a simple upgrade, then you can go directly to higher patches such as PL45.

Does anyone know of any reason why you have to upgrade to PL30 first?

The thread is:

SAPB1 2007 A Upgarde Requirement

Regards,

Douglas