The following Kb has been recently published and a hotfix is available. See  http://support.microsoft.com/kb/951526

 

SYMPTOMS

Consider the following scenario:

•You import a management pack to monitor certain network devices in a Microsoft System Center Operations Manager 2007 Service Pack 1 environment.

•You perform a network device discovery by using Simple Network Management Protocol (SNMP).

In this scenario, you may receive one or both of the following error messages:
Error message 1

Health service host process has stopped working

Error message 2

Health service Host process encountered a problem and need to close

In this scenario, the OpsMgr Health Service is still running correctly. However, the Root Management Server (RMS) becomes unhealthy or unusable. Additionally, the following event is logged in the Operations Manager log on the server on which you perform the network device discovery:

Event Type: Error
Event Source: HealthService
Event Category: Health Service
Event ID: 4000
Date: Date
Time: Time
User: N/A
Computer: ComputerName
Description:
A monitoring host is unresponsive or has crashed. The status code for the host
failure was 2164195371.
Problem signature:
Problem Event Name: APPCRASH
Application Name: MonitoringHost.exe
Application Version: 6.0.6278.0
Application Timestamp: 47b71437
Fault Module Name: HealthServiceRuntime.dll
Fault Module Version: 6.0.6278.0
Fault Module Timestamp: 47b71433
Exception Code: c0000005
Exception Offset: 00003d9d
OS Version: 6.0.6001.2.1.0.16.7
Locale ID: 1033

 

CAUSE

A defect in the SNMP networking module causes the HealthService service to become unstable or to crash. Therefore, the Root Management Server becomes unstable or unusable.

 

RESOLUTION

Hotfix information
A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.
If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.
Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support (http://support.microsoft.com/contactus/?ws=support)

Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites
To apply this hotfix, you must have System Center Operations Manager 2007 Service Pack 1 installed