I'm not really sure yet - but perhaps try this (seems to work for a test I tried) :-
- login to www.flickr.com using the mail address as the Yahoo! ID you have used for your pictures (if you've not already), this will enable you to create an account and give it a nice name.
- Go to http://closing.photos.yahoo.com/
- Got to "Move your photos" section and choose the flickr route - this will check [1] for the user account, but you may use a different flickr account if you want via a link (or not do option 1).
- Hit the "Import from Yahoo!" link
- Sit back and wait - mine took many hours to move if you have loads of piccies.
