I was using 'trash' as a holding location for posts that I wanted to recycle. I wasn't deleting those posts but they suddenly all disappeared anyway. Does anyone know why? Can I get them back? Help.

It wouldn't be Atahualpa that would do this. You could check your wp-config.php file and see if it has a line like the following.

define('EMPTY_TRASH_DAYS', 10 );

I ran across a host that had no trash set with their automated WordPress install so I suspect others could have a defined empty trash days.

Also instead of using trash for "recycling you could use draft instead.