Hope to bump this up. I'm experiencing the same thing on Open Solaris (X86) running SJWS 7.0U5 with the latest lbplugin (9.1.1b14) and require-monitor-data has always been set to false in the loadbalancer.xml, so I'm not sure what else to check other than start rolling back versions of the lbplugin.so.
[20/Jan/2010:15:08:36] info ( 1955): reports: Initializing lbplugin BuildId: GlassFish V2.1 aslb-b14
[20/Jan/2010:15:08:36] info ( 1955): CORE5076: Using [Java HotSpot(TM) Server VM, Version 1.6.0_13] from [Sun Microsystems Inc.]
[20/Jan/2010:15:08:36] warning ( 1955): reports: lb.runtime: RNTM2019: Daemon
http://localhost:9005 has been intialized.
[20/Jan/2010:15:08:38] info ( 1955): HTTP3072: http-listener-1:
http://wpvforum1:80 ready to accept requests
[20/Jan/2010:15:08:38] info ( 1955): CORE3274: successful server startup
[20/Jan/2010:15:08:41] catastrophe ( 1955): CORE3260: Server crash detected (signal SIGSEGV)
[20/Jan/2010:15:08:41] info ( 1955): CORE3261: Crash occurred in NSAPI SAF service-passthrough
[20/Jan/2010:15:08:41] info ( 156): CORE3050: Spawning replacement for worker process 1955
[20/Jan/2010:15:08:41] info ( 1956): reports: Initializing lbplugin BuildId: GlassFish V2.1 aslb-b14
[20/Jan/2010:15:08:41] info ( 1956): CORE5076: Using [Java HotSpot(TM) Server VM, Version 1.6.0_13] from [Sun Microsystems Inc.]
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