I had a client with only Dell servers and moitored by Opsmgr 2007 SP1.
I imported the Dell management pack and after a while I had this error:
Event Type: Error
Event Source: HealthService
Event Category: Health Service
Event ID: 4000
A monitoring host is unresponsive or has crashed. The status code for the host
failure was 2164195371.
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
Microsoft discovered an issue in the SNMP networking module that causes the HealthService to become unstable.
When I installed the hotfix my issue was solved!