Not on FireFox at all or on early netscape/opera or even on ie if javascript is turned off or if the user links in from a surfing history containing a page with bad javascript errors.
How about if you point the link at a simple page on a site you control such as
http://mysite.com/ebonysite2.html
and have an instant redirect (with your affiliate code) on the page. That should cloak your link code making it unalterable and also give a clean address for the surfer and will work in all browsers.
Any comments?