MySQL 5.1 Error with Rails 2.2

if you found yourself stuck with such error

ArgumentError (NULL pointer given):
     (eval):3:in `each_hash'
     (eval):3:in `all_hashes'

then this might be useful for you.

Actually i don't know why it happened but i reached that this only happened between Rails 2.2 and MySQL 5.1
when i downgraded to MySQL 5.0 everything went fine

of course it will be nice from you to dig and search inside to know WHY THIS HAPPENED but if you have no time AS WAS THE CASE WITH ME, such info can help you survive