I have the exact same problem. I did notice that the tool from the older version 3.5 RCLI worked ok, even with a vSphere 4 ESXi host. I hadn't realised that the output was a tgz, so once I renamed the files it produced for me I was able to verify that they were ok. However, I guess it's possible that ESXi 4.0.0 may have more files it's supposed to collect into that tgz.
EDIT. Hmm I see from your post dates that you must have been using that older version. Strange.
