Yes, I am using the same cmd.exe and it is running in administrative mode only. And I suspected the security settings and for testing I disabled firewall settings in order to allow nfs mount. I didnt check the event logs. Will check it.
I think ikegami and I were both thinking more of local security policies (e.g. maybe perl.exe is being restricted in some way). If it was the firewall then wouldn't they wither both work or both fail?