Delay between mirrors?

[#1]

I have my Linux webserver at home running Centos 5 and Virtualmin. I have my VPS with Eukhost identically running Centos 5 and Virtualmin.
After running yum -y update on both, the VPS updated from 5.3 to 5.4 but my home webserver is reporting no packages marked for update. Can I assume that different mirrors are a little behind and my home server will update soon? I have a cron job on Sundays to run the command anyway.

[#2]

More than likely, do you have a default server setup or is it just set to the grabbit and see setting?
Defendant on where the other server is connected the local mirror maybe faster to update.

[#3]

I just use grabbit and see.
I just run yum clean all then yum -y update and it is now updating as we speak.