Stack Error in method missing

I began having a problem with stack level too deep errors at different locations in my application after moving to rails 2.1. The code always seems to work after a server restart, but will fail again sometime later and then fail consistently. It appears that it is looping in the following code in method missing.

def methodmissing(methodid, *args, &block)

  method_name = method_id.to_s

  # If we haven't generated any methods yet, generate them, then
  # see if we've created the method we're looking for.
  if !self.class.generated_methods?
    self.class.define_attribute_methods
    if self.class.generated_methods.include?(method_name)
      return self.send(method_id, *args, &block)
    end
  end

  if self.class.primary_key.to_s == method_name
    id
  elsif md = self.class.match_attribute_method?(method_name)
    attribute_name, method_type = md.pre_match, md.to_s
    if @attributes.include?(attribute_name)
      __send__("attribute#{method_type}", attribute_name, *args, &block)
    else
      super
    end
  elsif @attributes.include?(method_name)
    read_attribute(method_name)
  else
    super
  end
end

It only seems to happen when looking up 'id' and the loop is happening on the line.

  if self.class.primary_key.to_s == method_name
    id

where the call to id causes an infinite loop on method_missing.

I have tried this with 2.1 stable and edge with the same results and on both a windows and linux box with webrick and mongrel with the same results.

I will work to find a simple example case, but wanted to post this in case someone else with more experience has some suggestions.