combining multiple calls to ScriptResource.axd

I am trying to minimize calls to ScriptResource.axd but i have failed. Below is the result

Uaing .Net 4.0, AjaxControlToolkit ver 4.1.60919.0 and ScriptManager is added as

<asp:ScriptManager ID="ScriptManager1" runat="server" ScriptMode="Release">
        <CompositeScript>
            <Scripts>
                <asp:ScriptReference name="MicrosoftAjax.js"/>
                <asp:ScriptReference name="MicrosoftAjaxWebForms.js"/>
                <asp:ScriptReference name="Compat.Timer.Timer.js" assembly="AjaxControlToolkit, Version=4.1.60919.0, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e"/>
                <asp:ScriptReference name="Common.Common.js" assembly="AjaxControlToolkit, Version=4.1.60919.0, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e"/>
                <asp:ScriptReference name="Animation.Animations.js" assembly="AjaxControlToolkit, Version=4.1.60919.0, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e"/>
                <asp:ScriptReference name="ExtenderBase.BaseScripts.js" assembly="AjaxControlToolkit, Version=4.1.60919.0, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e"/>
                <asp:ScriptReference name="CollapsiblePanel.CollapsiblePanelBehavior.js" assembly="AjaxControlToolkit, Version=4.1.60919.0, Culture=neutral, PublicKeyToken=28f01b0e84b6d53e"/>
            </Scripts>
        </CompositeScript>
    </asp:ScriptManager>

My website was working fine but suddenly customers started complaining that it is slow. I checked the website from client side and found that every single click takes approx. 10 seconds, whether it be a DB call or just a simple loop upto 30.

I checked and found that the time between Application_BeginRequest and Application_EndRequest is less than a second. Then on IE Profiler i came to know that there are various calls to ScriptResource.axd and so trying to minify these calls.

Kindly help and let me know what is wrong with these configs.

Edit No success so far in minifying calls to ScriptResource.axd. I am pretty much sure that

every single click takes approx. 10 seconds

because of these multiple calls to ScriptResource.axd. If it is something else which is causing this much delay then please guid me towards right direction.

There was a DropDownList in which, at client side, ~30,000 records were being loaded. This was unexpected. I replaced this DropDownList with a lookup screen and things started working as expected.