to be more specific, here is the detailed log of different browsers talking to ioftpd (script included).
http://d.padfly.com/ioftpd?download
the following link is given -
ftp://127.0.0.1/public/10.jpg
/public - virtual directory
/_public - dir mount whose contents are duped in /public
as a result, opera succeeds and iexplore fails
hope this'll help