It didn't worked for me for any of those webmails.
@Skierpetros,
yes even i had that same problem.
Gmail, Yahoo doesn't import all contacts. so what i did was, i exported all my contacts from gmail, yahoo and imported in to hotmail. then hotmail importer did imported all those contacts but there was that problem of /x40. So finally hotmail also didn't worked for me.
Thats why i got this FREE contacts inviter on my site and its working like a charm. check out if you want :
http://www.projectsplanet.com/importer.php