5.5.1 returning empty information on some VC:HostSystem attributes

I recently upgraded my environment to 5.5.1 and it seems like some information from the VC:HostSystem object is returning empty values.  I get zero's back for the following items which were working.  Can anyone else try a quick test with these and see if you get expected results?

System.log("esxHost.summary.hardware.numCpuPkgs: " + esxHost.summary.hardware.numCpuPkgs);

System.log("esxHost.summary.hardware.cpuMhz: " + esxHost.summary.hardware.cpuMhz);

System.log("esxHost.summary.hardware.memorySize: " + esxHost.summary.hardware.memorySize);

System.log("esxHost.runtime.bootTime: " + esxHost.runtime.bootTime);

Thanks!

Paul