Shutdown of DFSR Partner

I'd like to find out whether something that happened yesterday is normal
operation. Two DFSR partners, each being a folder target for a domain based
namespace. One is W2k3, the other W2k8. This folder target contains
approximately 450GB of data.

At 2:00PM yesterday one gets restarted for a Windows Security update. When
it comes back up, the first partner begins replicating the entire folder to
the partner that was restarted. The only logs in the DFS log are about the
Staging folder high watermark being reached, and then reset. This lasted for
almost 24 hours, until I changed the replication schedule to give myself time
to figure out why this is happening.

Is this just the partners verifying that they each hold the same data? If
so, why is the Staging folder being triggered? And if not, is this something
we can expect to occur every time a server is rebooted?