REDCINEX color grading send back to FCP7 problem

Hi guys,

this is my first time operating FCP - Red workflow,

so I transcode footages to Proress LT, and edit in FCP 7
(R3D raw footage's file names are remained the same, but I sync those Proress files and rename them)

export a XML, import it in RedcineX
color grading there,
then export a FCP XML
trying to import back in FCP7,
but the system says " Non-critical errors were found while processing an XML document"

what did I do wrong ?
I've tried many many times

thanks