Shift+Tab deletes last character of the previous field

Question

Hello All,

I have lots of controls in the form, but just two controls (Text Boxes) that have problem with the Shift+Tab. When I use Shift+Tab to move back to the previous field(s), the last character of these two fields are deleted. I have noted that the field won't stay selected (like other field) when we use the Shift+Tab, and that makes the last character removed from the field.

How can I fix this problem? Any help is greatly appreciated.

-V