Active Directory -- "Replicate Now" POPUP message ?

I have three Windows 2003 DCs, one at each site, and get
the below message when trying to force a "Replicate Now"

One or more of these Active Directory connetions are between domain
controllers in different sites. Active Directory will attempt to replicate
across these connections. For information about how to verify replication,
see Help and Support.

http://www.winvistatips.com/threads/one-or-more-of-these-active-directory-connetions-are-between-domai.707220/
claims that there is no error on the below, it is just an informational message stating that replication isn't immediately, it will be scheduled

Is there anything I need to worry about since I can create a new user in site #1 and the next day the user is in site #2 and #3, therefore replication seems to still be working without forcing it ?