About the focus move in table?

[黃慶 Kason Huang <kasonhuang kinposh com cn>]

Title: About the focus move in table?

hi guys:
anyone could tell how to change the focus in three tables(there is a lot of buttons in each table) with keyboard.
and I find that  the buttons focus in one table couldn't be changed smoothly.for example,when you press left key on keyboard,you expect the focus will move to the left button,however the focus maybe move to the a button on the bottom of the table.

a table's layout like following picture:(24 buttons in one table)

when focus in 14 button,i press down key on keyboard.i expect the focus will move to the 20 button,the result is the focus moves to the15 button or other button,not 20 button.the same thing is happen to the 18,20 button.do anyone knows how to handle with the problem? or how to control the focus in a table?

Thanks in advance!
kason