I am also running into this problem where the ajax update positions the scroll bar at the topmost part of the page. Here's my scenario:
I am developing an application to allow students to apply for admission to the university. On the page where they select a major, there is a dynamic user control that will display a supplemental application for particular majors, let's say "Music" in this example. That "music" user control contains a checkbox list that has autopostback=true and a selectedindexchanged event that fires. Depending on the selection, additional controls (contained within an ajax panel) may appear.
When I click the checkbox, the loading panel image appears over the section, the new area is set to visible, but then the page scrolls back to the top.
Here is a rough code snippet from the application:
telerik:RadAjaxPanel runat="server" ID="RadAjaxPanel1" LoadingPanelID="alpLoading">
bsu:IntendedMajor runat="server" ID="bsuIntendedMajor1" StartTabIndex="8" Required="true" ItemCount="1" OnIntendedMajorSelectedIndexChanged="bsuIntendedMajor1_IntendedMajorSelectedIndexChanged" />
Intended Major user control (no ajax panels on this user control)
- Loads the appropriate major user control, in this example "Music"
Music user control (no ajax panels on this user control)
<asp:Label runat="server" ID="lblMusicProgram" Text="Which music program(s) are you interested in (select all that apply)?" AssociatedControlID="cbxlMusicProgram"></asp:Label>
<asp:CheckBoxList runat="server" ID="cbxlMusicProgram" AutoPostBack="true" OnSelectedIndexChanged="cbxlMusicProgram_SelectedIndexChanged"></asp:CheckBoxList>
Based on selection:
pnlMusicEducation.Visible = false;
pnlMusicTechnology.Visible = false;
I'm not sure if this is enough of an explanation or code to fully understand the problem, so if I need to open a support ticket or submit additional details, please let me know.