Error: ZBX_TCP_READ() failed [Interrupted system call]

[LPby]

I have Zabbix server v1.4.6 (MDV2009) and Zabbix agent v1.4.5 (RHEL4U7).
All work correctly.
But!
I've added my own item to RHEL box:

[root@RHEL zabbix] cat zabbix_agentd.conf
..........
UserParameter=raid,sudo mpt-status | grep -c ONLINE

And get it on MDV2009:

[root@MDV2009 init.d]# zabbix_get -s RHEL -k raid
2

Seems that all works......

But:
I added item (screen in attach)

[root@MDV2009 init.d]# cat /var/log/zabbix/zabbix_server.log
.............................
 17258:20090310:184226 Timeout while answering request
 17258:20090310:184226 Get value from agent failed. Error: ZBX_TCP_READ() failed [Interrupted system call]
 17258:20090310:184226 Host [rhel]: first network error, wait for 15 seconds
 17258:20090310:184226 Parameter [raid] will be checked after 120 seconds on host [rhel]

HELP me please!!!

[LPby]

I've changed raid to raidstatus and all begin work.
How could it be?