使用ActiveRecord和Rails将数据插入postgresql数据库会出现此错误：RuntimeError：ERROR C22003 Minteger o

I am using Ruby 1.8.6 and rails 2.1.1 (I have tested rails 2.2.2 as well). I have been using Sqlite3 and I recently migrated to Postgresql 8.2.6 for production use. Now this error shows up. The interesting thing is that when I copy the insert statment and use psql to directly insert it into postgres it works fine. I guess the problem is somewhere on the rails level. But, I have no idea what it is. So if anybody knows what the problem is or how to fix it please let me know.I am using Ruby 1.8.6 and rails 2.1.1 (I have t