[Libguestfs] Python Hivex Assertion Failed

Good afternoon, I am working with the hivex python bindings and having trouble with an assertion failure. The code I run is based on the blog post from 11/28/10 and is: import hivex h = hivex.Hivex("ntuser.dat") r = h.root() key = h.node_get_child(r) The assert failure happens when I call any of the "node" functions, even "node_name()". The error message I get each time is: python: hivex-py.c:52: get_handle: Assertion 'obj' failed When I print r (h.root() result), I get a long integer "4128". (Which makes sense -- that would be shortly into the second bin, where the root of the hive should be). The hivex.3 man page indicates that the return value for the root() function should be a handle, aka integer, so it seems to be right. I don't think it's the hive -- i tried a couple different ones, albeit all from the same machine. I also ran it with a perl based registry library and it was fine. I'm using Ubuntu and python 2.6. Any suggestions on what the problem might be? Thanks! Elizabeth