I followed all the instructions on Altova's web site and got it working for version 2005 edition 3. Everything works except for the issue that Christian Ashby mentioned - I just rename elements and attributes from the properties dialog on the side. That seems to get around the issue.
I cannot get this to work in 5.0.1 using Altova's instructions. It might be because I'm using winxp dll's in a win98 "bottle"