problem with debian jesse arm on cubox. apt-get update fails [SOLVED]

putting solved on it so far

here is the error:

root@cubox4:~# apt-get update
Hit http://ftp.us.debian.org jessie InRelease
Hit http://ftp.us.debian.org jessie/main Sources
Hit http://ftp.us.debian.org jessie/contrib Sources
Hit http://ftp.us.debian.org jessie/non-free Sources
Hit http://ftp.us.debian.org jessie/main armhf Packages
Hit http://ftp.us.debian.org jessie/contrib armhf Packages
Hit http://ftp.us.debian.org jessie/non-free armhf Packages
Hit http://ftp.us.debian.org jessie/contrib Translation-en
Hit http://ftp.us.debian.org jessie/main Translation-en
Hit http://ftp.us.debian.org jessie/non-free Translation-en
Reading package lists... Done
W: There is no public key available for the following key IDs:
7638D0442B90D010

proposed solution for now is here:

http://devget.net/linux/how-to-fix-no-public-key-available-for-the-following-key-ids-in-debian/

short of it for the solution is:

apt-get install debian-keyring debian-archive-keyring

 

then do the apt-get update