Easiest solution (since this is a reader-writer deadlock) would be snapshot or read committed smapshot isolation.
Can you investigate and see what these two pages belong to (can see the table, not the index)
1:6968174
1:6824253
Also can you post all indexes on PSX_PUBLICATION_SITE_ITEM
I suspect this is a key-lookup related deadlock.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability