Here's another tool you can play with while working your firewall/permissions issue afflicting your WMI:
http://www.paessler.com/tools/wmitester
PS - On an unrelated note, please keep in mind that PSRemoting and WMI can be mutually exclusive (i.e. generally speaking, there is no need to enable psremoting in order to use WMI against a target server. Of course, once you do you can get tricky with it. But not required.