I went throw the links you have given but problem still there.
I am also facing the same issue mentioned.
The problem is i have some serverside validation in a Name Column. So after entering the name postback occur and validate the name and rebind the grid. At that time focus lose and user needs to do a mouse click.
Like while doing the post back keep the row and column name, then after postback based on stored cell details set the focus to next cell. Because during the postback i am rebinding the grid so surely the grid will lose the focus.
Please suggest if there is anything for this issue.