As you properly know there are some significant differences in the way SCCM/OSD works before SP1 and after SP1.
One being the OS target drive during the WinPE phase (D or E instead of C), and also weather or not you have to "press OK to accept that OS deployment is about to start, and your DeployCD should be removed" (I use CD in the form of .wim loaded into WDS for my "Mixed mode" customers).
Also the difference between PE 2.0 from WAIK 1.0, that lack some NIC and Storage drivers that the 2.1/1.1 version have.
Now where am I going with all this, well I was with this customer who claimed to have SCCM SP1, and sure enough, All clients had the SP1 version, an everything looked very SP1, but the OSD part still acted pre SP1!
so I thought id better check for versions, and found that I couldn’t really find any info on version numbering for SCCM. I then had to go back and startup all my old SCCM test labs to check for the different versions. It turned out the customer was running a SP1 prerelease, and that was why I ran into problems.
To save everyone the time here is some of the SCCM versions
– SCCM R1: Version 4.00.5931.000
– SCCM sp1 (prerelease): version 4.00.6086.1000
– SCCM sp1 :Version: 4.00.6221.1000