Thanks Tim! I appreciate you doing this. I'll post the answer again for the benfit of anyone experiencing the same problem:
From earlier post
You need to slipstream service pack 2 into your CD based RIS. The first thing you need to do is copy your Win2k media to a distribution share on a server/workstation. Then run the service pack with the "x" switch to unpack it: W2ksp2.exe /x. It will prompt you for a directory to unpack the service pack to. Choose a DIFFERENT directory than the one you loaded the win2k media to. Once you've unpacked the SP you'll notice that all of the service pack files will be in the directory that you specified. To slipstream the service pack into your media you'll run the update.exe that was extracted from the service pack: FolderYouSpecified\i386\Update\Update.exe -s:%Path%\Folder_You_Placed_The_Media_In (e.g. C:\SampleFolder\i386\Update\Update.exe -s:E:\Win2000). Once the service pack is slipstreamed into the media delete your current CD based image and load a new image from the distribution point that contains the slipstreamed media. You can now create images with service pack two in them and you won't have a problem. If you need a quick fix to get around your problem you can replace the NTOSKRNL.EXE file from your CD based image on the server with a NTOSKRNL.EXE file from an SP2 machine (i.e. copy %SystemRoot\system32\NTOSKRLN.EXE from a machine with SP2 and copy it over the \\RIS_Server\REMINST\Setup\English\Images\win2000.pro\i386\N TOSKRNL.EXE file on the RIS server). This tricks the RIS server into thinking that it?s CD image is Win2k SP2. However bear in mind that if you do a new CD based install with the substituted NTOSKRNL.EXE file then the image will fail because the rest of the media is not SP2.