Transactional Replication Moniter's distributers to subscribers shows error messages.

I am using transactional replication type in sql server 2005 with from many Publishers to one subscriber topology.

The Replication monitor's distributers to subscriber tag shows the following error messages.

Error messages:
The process could not bulk copy into table '"dbo"."sysdiagrams"'. (Source: MSSQL_REPL, Error number: MSSQL_REPL20037)
Get help:
Batch send failed
Violation of PRIMARY KEY constraint 'PK__sysdiagrams__08EA5793'. Cannot insert duplicate key in object 'dbo.sysdiagrams'. (Source: MSSQLServer, Error number: 2627)
Get help: http://help/2627

To obtain an error file with details on the errors encountered when initializing the subscribing table, execute the bcp command that appears below. Consult the BOL for more information on the bcp utility and its supported options. (Source: MSSQLServer, Error number: 20253)
Get help: http://help/20253 "AUTOERP"."dbo"."sysdiagrams" in "C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\ReplData\unc\PARI_AUTOERP_REPLICATION_FROM_MSSQL\20100429120926\sysdiagrams_129.bcp" -e "errorfile" -t"\n<x$3>\n" -r"\n<,@g>\n" -m10000 -SERP4 -T -w (Source: MSSQLServer, Error number: 20253)
Get help: http://help/20253

Please give me the proper solutions to solve this problem.

Thanks a lot.