I've had this problem before and so I'm going to guess that it has something to do with authorization and you're being redirected back to the root directory. Try adding the following to the web.config file in the destination directory:
For a particular page add:
<br />
<location path="[YOUR.FILE]"><br />
<system.web><br />
<authorization><br />
<allow users="*"/><br />
</authorization><br />
</system.web><br />
</location><br />
.. or for the whole directory...
<br />
<system.web><br />
<authorization><br />
<allow users="*"/><br />
</authorization><br />
</system.web><br />