zabbix server crashes after unsuccessful insert to postgresql database, happens after a short time zabbix server runs (~3-4 mins).
server log says:
15654:20071204:145038 Query::insert into trends (clock,itemid,num,value_min,value_avg,value_max) values (1196766000,20163,1,0.000000,0.000000,0.000000)
15654:20071204:145038 Query failed:PGRES_FATAL_ERROR:ERROR: duplicate key violates unique constraint "trends_pkey"

15654:20071204:145038 Query::update items set nextcheck=1196769218,prevvalue=lastvalue,lastvalue='0',lastclock=1196769038 where itemid=20163
15654:20071204:145038 Query failed:PGRES_FATAL_ERROR:ERROR: current transaction is aborted, commands ignored until end of transaction block

15654:20071204:145038 Query::select distinct function,parameter,itemid,lastvalue from functions where itemid=20163
15654:20071204:145038 Query failed:PGRES_FATAL_ERROR:ERROR: current transaction is aborted, commands ignored until end of transaction block

the number of hosts monitored ~140, each with ~25 items