The status window in the build should display the RGUID of the culprit.
But your error message is an improperly formated registry entry in the RGU of OEM in the user_oem folder. Or an improperly formatted RGU all together. I don't use ppckitchen's buildos, but an older version.
Ask your question in that kitchen's thread and I'm sure you'll get the answer you are seeking.
Here's the thread:
Sticky: WM6.5 build 21501 kitchen