All custom fields disappear when using Quick Edit

I've just had a really weird problem with CustomPress.

I'm running a WP MultiSite v3.0.4. I'm using the Genesis framework and using CustomPress to manage my custom fields and custom taxonomies.

I had custom field entries for phone/email/web/address for a number of posts in a directory I'm building. When I use Quick Edit to make any change all the custom field entries for that post disappear!! I tested it with changing category and changing author. Once I click the Update button my custom fields vanish.

This is obviously a really serious problem when using WP as a CMS especially for a directory site. Any idea what is happening there?