Hi frank.pedro,
Yes this behavior is because of UpdatePanel,
For example suppose you have a two controls on the page, gridview, and label,
lets say gridview is inside UpdatePanel, and label is not.
now if you trigger asynchronous postback from inside UpdatePanel, ONLY the inner contents of UpdatePanel changes, all the remaining controls that are outside of that panel doesnot refresh, even if you assign then some value/visual representation from the server. This helps AJAX developers to speed up web application, because when server sends a response back to the browser, only inner contents of Update Panels are sent, and not the whole page.
To solve your issue you simply should place ALL the controls you want to be refreshed inside another UpdatePanels (add as much as needed - the more UpdatePanels means more overhead of deserialising respone in the browser). To refresh that UpdatePanels now you have two options:
1) Simplest one - just assign the "Always" value to the "UpdateMode" property of the panels - this says the framework - that these UpdatePanels should be refreshed Always - on every asynchronous postback
2) More sophisticated - Assign "Conditional" value to the "UpdateMode"property to that UpdatePanels. - In this case the Panels are only refreshed - if control triggered postback from inside them (each control refreshesd it's own Panel). And you have an option of refreshing such a UpdatePanels from the server - jast write this inb code behind: UpdatePanel1.Update();
Hope this helps