Anonymous behaviour of DataGrid focus with the Tab key??Please Help

Question

Hi, I have made an application in C#. My some forms have DataGrid along with some text box and buttons. For the first time when I start pressing Tab key the cursor goes everywhere i.e. every cell of DataGrid. In the next cycle it goes to all textbox, button but when it goes to DataGrid, it it skips the starting cells and goes directly to last cell and this goes on with every cycle. I have checked this by making small application. Even it also has the same problem. Is there any way to get rid of it?? How can I make a fix to avoid this? Thanks in Advance. Regards, Ashish