I think you still need msn (12 digits) from the phone not the sn or maybe the db or the calc are missing something.
example
http://forum.gsmhosting.com/vbb/6300483-post1.html
SERIAL NO: PA0730B07904 gives
NCK8886467799374288
NSCK7322231365553002
SPCK3153573741994394
UCCK7581888879931936
UNCK8886467799374288
UNSCK7322231365553002
USPCK3153573741994394
but with lgtool UNSUPPORTED MSN
However lgtool allows only 10 digits, so wait for the lgtool supporters to make it clear.