When using EYB on the iPad it should always default to the full site. We've added a link - the green strip at the top of the screen as a link to the mobile site. It should only go to the mobile site if you click on this link. I've been using EYB on the iPad and can't reproduce the problem you're having.
Can you try clearing your cache and history. Go to your Settings - select the Safari icon - and click on the Clear Cache and Clear History buttons.
If this still doesn't work can you mail me at firstname.lastname@example.org and we'll investigate further.
Harlen - did you try clearing your cache, as Fiona suggested for Cati?