I believe it's ESX4.0.0. There are various logs in /var/log/ vmkernel and others (I'm not logged in right now) and more in the folder /var/log/vmware/ I looked at all of them. I grepped for storage and latency but found only the ones above. Like I said in reply to your question, I see nothing about storage or latency in the main log (/var/log/vmkernel).
I got a cpu softlock of over 200s (which I suppose is 200 seconds) today on one of my VMs. No mention of it in any logs. The performance graphs didn't seem to indicate anything unusual.