Strange Record not saved errors

I have a site with an acts_as_authenticated based login which has
started throwing up some strange errors. Until a few days ago
everything worked fine but all of a sudden 'RecordNotSaved' errors are
popping up in my logs.

When I check the database, it looks like the record _is_ saved but I
think users get an error so I'm starting to see a lot of double/triple
entries for the same user. It doesn't happen all the time and I can't
really reproduce it myself and the log entry is not very helpful so I
have no idea how to solve this.. I am not even sure which direction to
look.. could it be related to mysql performance errors or something?

This is the error I'm getting:

A ActiveRecord::RecordNotSaved occurred in account#signup:

  ActiveRecord::RecordNotSaved
  [RAILS_ROOT]/vendor/rails/activerecord/lib/active_record/base.rb:
1398:in `save_without_validation!'

this looks like it happens when you try to sign up a new user. does it happen with other actions aswell or is it specific to signup?

What does your controller function for signup look like and can you post the user model?

In my user model I have these validations that could be causes problems for you if they are present in your model.

validates_presence_of :login, :email
validates_presence_of :password, :if => :password_required?

validates_presence_of :password_confirmation, :if => :password_required?
validates_length_of :password, :within => 4…40, :if => :password_required?
validates_confirmation_of :password, :if => :password_required?

validates_length_of :login, :within => 3…40
validates_length_of :email, :within => 3…100
validates_uniqueness_of :login, :email, :case_sensitive => false
before_save :encrypt_password

Regards
Ivor

You haven't recently started using clustered servers, have you?