> Usually HTT copies all files as HTML files only. But

Properly configured you can not get asp, cgi, jsp, sql or any other server
side code, only the html output and referenced files (jpg, css...)

> in my case default.aspx(Original file extension) is
> copied as it is. 

1) the site isn't running the script but is instead returning the actual
file.
2) the site allows access to the directory and there's a reference to that
directory.

> My log file doesnot conatain any errors related to
> this page.
none expected, it's a server configuration problem