Previous rows display when a new row add in GridView (in UpdatePanel) after hitting enter

I am having a problem in GridView using UpdatePanel. I have UpdatePanel which contains a GridView. When I enter rows in GridView and refresh a page it remove rows from Grid and if I enter again it shows only new entered row, works fine.

But when I enter few rows in Grid then click on address bar hit enter on it, it removes the rows from Grid and when I again enter a row again then it shows new with previous rows.

Can anybody tell me where am I doing a mistake.

Thanks in advance.

It works fine in debug mode but when I deploy the application on server, it shows previous records with new record.

Any idea?

Thanks in advance.