build identifier: 20090920-1017

merging table cells and splitting them again results in "inconsistent column count" error on table.

reproducible: always

steps to reproduce:
in birt report designer 2.5.1
- create new report
- use classicmodels sample database as data source
- create data set with select * from customers
- drag data set to layout to create table
- group on customer
- in group 1 summary row, merge all cells except last.
- split the newly merged cell
- preview.

error "the table report.body[0] has inconsistent column count" appears on table
i remember there's a similar bug before. maybe it's a duplicate.
duplicate. please try the latest build of birt.