Text Box Looses its content and focus while typing

I have asp.net page that has Scriptmanager, update panel and timer on it, when i set my cursor focused and keep it for few seconds it looses it focus from the text box and cursor looks to be no where. and also sometimes while typing text on text boxes and move to next i loose complete text or half of it from the previous text box.

 

What should be the issue ?what should be checked and done to sort out this issue