This is an interesting errno. the Single Unix Specification defines it as being 'Reserved', and gives no further help. The Linux source uses it in a few places for what appears to be networking related (eg: the network card has no link). Man pages around the Internet imply that it's a filesystem error -- the file could not be found because a link to the remote host is down.
if you get this error, good luck, and please, let us know how you did it :)
lib/main.php:944: Notice: PageInfo: Cannot find action page