I haven't heard of any problems with aspx and the templates, in fact I know of one site that is using them without problems:
https://scsapps.unl.edu/ConferenceRegis ... ation.aspx
From your second post I'm guessing that you don't have the templatedependents files on your server.
There is a document that outlines how to set up the templates on a server other than www.unl.edu.
http://ucommdev.unl.edu/webdev/communit ... c.php?t=31
My guess is that's the missing piece to the puzzle.
You CAN point to the existing template files on www.unl.edu - that's fine. But here's some things to note -
Drawbacks: Can't fully secure your pages if you're using SSL, potential speed problems if you're grabbing the ssi files remotely, and users cookies for contrast and homepage preferences don't get handled without extra work on your part.
So that's the rationale for distributing the templatedependents files to other servers. The big thing to note though is that those files need to be periodically updated.