When we have Peer to Peer (P2P) replication in place on SQL Server 2008, probably we would see a conflict
1) conflict of type 'Update-Update' was detected at peer 2 between peer 1 (incoming)
2) conflict of type 'Update-Delete’ was detected at peer 2 between peer 1 (incoming)
Microsoft has confirmed that this is known issue with P2P replication, and Microsoft has released a fix for this with Cumulative hot fix for SQL Server 2008 SP1. I am penning down some links for you as a point of reference for troubleshooting P2P conflict.
-- Hemantgiri S. Goswami (http://www.sql-server-citation.com )