Custom Field Values Not Saving

I have this same problem in WordPress 3

Described here: http://www.blogging-secret.com/another-bug-for-wordpress-25-custom-field
and here: http://wordpress.org/support/topic/163769?replies=20

I hope someone has a workaround that works. One guy said to try saving a post before adding custom fields, but that hasn’t helped me. The custom field values still disappear.