.net - Asp:treeview Suddenly Firing full-page postback? -

i have older web-app runs under .net framework 2.0, , have page uses asp:treeview control.

at point last month or two, no change application, has happened users reporting treeview acting strangely, , on investigating, click or expansion of node on treeview seems doing complete re-load of entire screen, rather asynchronous updates occur.

we have users experiencing in both ie9 , ie10, have users on ie10, @ least, not having problem. web server windows 2008 r2 sp1.

i have asp:calendar control on page acting strangely, haven't been able quite pinpoint if that's postback issue or else, not sure if it's related.

i'm not getting javascript error referenced here: http://www.hanselman.com/blog/bugandfixaspnetfailstodetectie10causingdopostbackisundefinedjavascripterrorormaintainff5scrollbarposition.aspx ...but did try applying hotfix, since symptoms described closest have found, didn't help.

i've gone several versions of application go year or more , still on our test web server reference, , of them exhibiting behavior.

i'd appreciate suggestions on ways troubleshoot this, if not actual thoughts on solution. i'm @ bit of loss.

thank you.

i not sure if still relevant you. faced similar scenario lately , solved assigning null onbeforeunload event of window object on affected page below

<script type="text/javascript">  window.onbeforeunload = null; </script> 

try , let me know if works you.