"Refresh all" button is for refreshing auctions status information, such as "paid", "received item" etc.
It does not refresh auction's current bid.
Refreshing current bids information is done by server on background few times per day for active auctions only.
Please check this FAQ section for more information:
http://www.myibay.com/login/faq/4/#q13
If you want to force a refresh for some particular auction, you have to to go details and click "Refresh" from there.
Or simple re-add this auction id into your list.
When you use Windows-version of myibay, then you can simply select auctions you want want refresh and click "Refresh" so it will update auctions your chose.
Please feel free to contact me if you have more questions or suggestions.
Thanks.