CCBC-150, CCBC-225: Don't miss out callbacks

Change-Id: I59f07a95d591ded06ac43be1cb88c19f9d8e2fad
Reviewed-on: http://review.couchbase.org/28047
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>