Problem with focus with an ALV grid using object methods

Hi, i have an editable ALV and there is something wrong that we haven't been able to solve it yet, hope you can understand my explanation

Supose a grid 2 x 5

cell 1 - cell 2 - Cell 3 - Cell 4 - Cell 5

001 John Doe

So when a press tab or enter to the any cell diferent from cell 1 the focus get back to the cell 1, and i have to tab ( in this example) 3 times to fill cell 4, and then 4 times to fill cell 5

Any ideas???

ttorres