We have a large (10.000 plus articles) news site. When I enable the breadcrumbs I get a fatal memory exausted error in when viewing category some (not all) archives.
Fatal error: Allowed memory size of 536870912 bytes exhausted (tried to allocate 128 bytes) in **********/public_html/wp-includes/cache.php on line 406
My memory limit has been set to memory_limit = 512M, from 128, to 265 and still with 512 the problem persists..
This is without any other plugins and with the default 2011 theme. There is more than enough RAM present on this server, which runs only a few websites (no shared hosting).