Rails 3 and 2.3.8 fail to save a model called "Update" -

i have this:

class update < activerecord::base   has_many :comments end  class comment < activerecord::base   belongs_to :update end

update.first gives:

#<update id: 1, body: "update 1", ...>

comment.first gives:

#<comment id: 1, update_id: 1, body: "comment 1", ...>

when doing this:

comment.first.update_attribute(:body,"this fails saved")

and comment still contains "comment 1" i.e. record silently fails updated.

now comes weirdest part. when remove 'belongs_to :update' comment update_attribute method succeeds.

any ideas?

ERT