You cannot update GUPs manually. They need to get the specific content from the SEPM.
What you're doing is updating the SEP client (acting as GUP) with the latest content. That should be fine.
But the content that the GUP hands out to clients cannot be updated manually and can only be gotten from the SEPM.
Please read thru this article:
Can a GUP be updated manually using definitions files ?
http://www.symantec.com/docs/TECH181097
https://www-secure.symantec.com/connect/forums/downlaoding-gup-content-manually