Drools Flow BAM Module(5.1.0.M1) - Primary Key of String type creating problem

I am planning to use Drools Flow BAM (5.1.0.M1) module to store the processes instances for audit purpose. I generated the DDL with the help of Hibernate Tools against the MYSQL 5.1(INNODB)

DDL for the 2 tables are given below – the interesting part is the "id" column as "varchar" ---- this gives error when we try to execute the DDL against the mysql.

create table AUDIT_NODE_INSTANCE_LOG (
id varchar(255) not null auto_increment,
type integer,
nodeInstanceId varchar(255),
nodeId varchar(255),
processInstanceId bigint,
processId varchar(255),
DATE datetime,
primary key (id)
) ENGINE=InnoDB;

create table AUDIT_PROCESS_INSTANCE_LOG (
id varchar(255) not null auto_increment,
processInstanceId bigint,
processId varchar(255),
START_DATE datetime,
END_DATE datetime,
primary key (id)
) ENGINE=InnoDB;

The error we get is

Error: Incorrect column specifier for column 'id'
SQLState: 42000
ErrorCode: 1063

Just to test with different column name such as "primaryid" - we still the same error.

If i change the column type to "bigint" - the tables get created fine.

I think with the "native" strategy - the column type should be changed from 'String' to 'long'

Thanks
Vijay
p.s. I used a naming strategy for the hibernate that's why the above table names.