Hello,
This is a general question really. I had read some where, it may of been an Microsoft whitepaper or blog I am really not sure as I dont have the link right now.
Basically, the person was describing that (of which he referred to AJAX.Net 1.0) when using an update panel, although you would expect only the controls and components associated to be updated/refreshed, the entire page is submitted with the request in the update panel.
Obviously this defeats the purpose of AJAX when the design is to minimize traffic sent to and from the server. In this case you might as well do a full post back for the page. I guess from a cosmetic point of view, AJAX.Net does the trick as intended but behind the scenes doesn't do what you would expect.
Now this could well of been resolved in later versions I just can't confirm this. I have searched Google high and low for an answer.
What the person said was to use JQuery as this offers true optimized traffic flow when updating, which of course it does, so this is why I ask have Microsoft done the same with their later versions.
Just thought I'd ask you lot before attempting the impossible task of asking someone in Microsoft.
I'll have a look for the link when I get home and if I find it I'll add it here just so you don't think I'm off my rocker. :)