works for me, after a few tries. it seems ebay tries to redirect the N900's browser to a non-existent page during login, resulting in an error message, but it's succesfully logged in afterwards.
this site seems to redirect based on the User-Agent of the browser. with the N900, it tries to redirect to site.igv.cnr.it/xampp, which requires authentication. if you enter the url with /home directly (http://site.igv.cnr.it/home/), it works. at least on mine.