Syncrepl: Two step forward, one step back

Hi,

I still can't figure out what to think of this:

I have a mirrormode setup. One server has the database, the other starts 
empty. The data is slowly propagating from server-1 to server-2, but 
when I monitor the process by counting how many objects are created on 
server-2 below the root object, it is not strictly increasing.
All object below the root has DN: o=...


Is see output like this:
# slapcat | grep 'dn: o=' | wc -l
601
# slapcat | grep 'dn: o=' | wc -l
622
# slapcat | grep 'dn: o=' | wc -l
620
# slapcat | grep 'dn: o=' | wc -l
628

Why does server-2 "regret" already replicated objects?

Is this expected behaviour?

/Peter