To the attention of jbucks, topic http://wordpress.org/support/topic/custom-fields-data-disappears-after-a-few-mins?replies=7, or everyone who knows what I'm going to tell.
Don't seem real to me that maybe here I found the solution. But the topic has been closed (why?? Even if is resolved, someone like me may need it again), so I must open a new one, in hoping that the author of that post -jbucks- or anyone else who knows the answer, can read me.
I have custom fields of a (1) post that disappears by themselves, about every 24 hours.
They disappears from the database, from meta custom fields box in the WP post edit screen and, of course, from editor drop-down menu and visualization on website.
I would like try your code, but I'm not just as good technically (and in English), so I don't understand what your "land cost" in particular refers to.
I'd like to know if your land_ cost is the meta_key or the meta_value, so that I can replace it with mine.
Actually I'm already trying as it is and seems to work anyway, even if now it's too early to tell.
Mine is not a custom type post, but a normal post (review of a book) to which I added the custom fields (Publishing House, Preface, etc.).
Thanks in advance for help.