NetBeans 6.7 Beta - 为什么它认为某些表没有主键？

I am using NetBeans 6.7 Beta to create entity classes from a MySQL (version '5.0.45-log') database. NetBeans accepts most tables, but rejects certain ones consistently (I can't see a pattern), saying they have "no primary key". All tables are using the InnoDB engine. All tables have primary keys of one or more columns. The MySQL query browser and NetBeans' internal database navigator both agree that all tables do, in fact, have a primary key. What's up?I am using NetBeans 6.7 Beta to create entity c