It would be worthwhile to get your hardware vendor involved as ESXi is reporting a hardware fault. Some more info on machine execption checks can be found here - http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1005184.
Do get access to the system logs you'll want to change the location as currently they are not stored in a manner that will keep the files past a reboot - http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2032823.
