Active record is getting confused with some complex has_many conditions

I have this has_many clause

has_many :top_comments, :order => 'created_at asc', :conditions => {deleted => false}, :limit => Comment.comments_to_display , :as => :commentable, :class_name => 'Comment'

it works fine in 2.3.5

in 3.0 I needed to change it to

has_many :top_comments, :order => 'created_at asc', :conditions => "deleted = 0", :limit => Comment.comments_to_display , :as => :commentable, :class_name => 'Comment'

something was making arel double escape comments (eg. ''comments''.'deleted' = 0)