MapPath and default web site

[Guest]

When the web site is not setup as the default then MapPath("virtname") returns the correct physical path for a virtual directory which has been setup.
However, when the web site is setup as the default web site then MapPath("virtname") doesn't return the correct physical
path.

For example,

http://localhost/mws/default.aspx

MapPath("virtdir") in this instance correctly returns "C:\mws\data"

Now I set this web site as the default and type

http://localhost/default.aspx

MapPath("virtdir") now incorrectly returns "C:\inetpub\wwwroot\mws\virtdir"

Any suggestions on how to get the correct location independent of whether the web site is default or not.

Steve