youtube sync doesn't appear to do anything

Issue Summary

I installed asset, created a content type.
Create a node, click Insert Asset, window pops up - click YouTube sync.
It asks for a Youtube user name, which I supply, but nothing appears in the directory window.
So I got a Youtube developer key for the domain, added in the config still nothing.
Checked my Youtube account, has a favourite, a playlist.
So I try again... click Youtube sync, doesn't ask for account, says "Click next to import your YouTube Videos and Favorites." then the usual fields to fill in when creating an asset.
Clicking next with the fields filled in or not - nothing happens.
Checked the database, asset_youtube_user has my uid and Youtube username ok.

What am I missing?
Also I can't see an option to change youtube username or remove it.