Hey Dreidrage,
Unfortunatly, 2 of the 3 os's you mention in your mail, we do not officially support. Vista especially, because of it's new security mechanisms, we've had to spend a great deal of time reworking the Qube! installer to deal with Vista's specific requirements. We are planning on supporting Vista, and will be officially supporting it as of 5.3 or later. (we are currently at 5.2)
This goes for Leopard as well. Since Leopard is also fairly new, we havn't fully qualified the platform for use yet.
As far as I can see, you don't have very many options unfortunately. However this is what I know from using Vista.
Qube! 5.2 should behave oddly specifically because of the way Vista runs it. You'll find the qb.conf file not in the windows directory, but in your installation user's home directory under LocalSettings/VirtualStore/Windows
You'll also find that you may need to run the qbservice routines manually to get them to configure your host properly. We'll probably be calling for Beta users for 5.3 soon since it is in working order, and is Vista capable now.
Thanks,
A