radcombobox - Telerik control events always being triggered -

i'm using telerik combo box create cascading multi-select drop down lists.

i have several drop down lists on page ddlproject, ddlunit, ddldiscipline, ddldoctype.

i using telerik radajaxmanager trigger updates of controls , markup of follows:

<telerik:radajaxmanager id="ajaxmanager" runat="server" defaultloadingpanelid="lpnlloading" >         <ajaxsettings>             <telerik:ajaxsetting ajaxcontrolid="ddlproject" eventname="textchanged">                 <updatedcontrols>                     <telerik:ajaxupdatedcontrol controlid="ddlunit" updatepanelrendermode="inline"/>                     <telerik:ajaxupdatedcontrol controlid="ddldiscipline" updatepanelrendermode="inline" />                     <telerik:ajaxupdatedcontrol controlid="ddldoctype" updatepanelrendermode="inline" />                     <telerik:ajaxupdatedcontrol controlid="ddlphase" updatepanelrendermode="inline" />                 </updatedcontrols>             </telerik:ajaxsetting>             <telerik:ajaxsetting ajaxcontrolid="ddlunit" eventname="textchanged" >                 <updatedcontrols>                     <telerik:ajaxupdatedcontrol controlid="ddldoctype" updatepanelrendermode="inline"  />                 </updatedcontrols>             </telerik:ajaxsetting>             <telerik:ajaxsetting ajaxcontrolid="ddldiscipline" eventname="textchanged">                 <updatedcontrols>                     <telerik:ajaxupdatedcontrol controlid="ddldoctype" updatepanelrendermode="inline" />                 </updatedcontrols>             </telerik:ajaxsetting>         </ajaxsettings>     </telerik:radajaxmanager> 

ddlproject updates ddlunit, ddldiscipline , ddldoctype.

ddlunit , ddldiscipline meant update ddldoctype finding textchanged event being fired when either of these controls changed.

i've tried commenting out ajax manager see if ddlproject_textchanged being called , it's not, when ajax manager on page. ajax manager enabled suppress page postbacks plus displays loading panel each of comb boxes think gives user experience showing when loading.

all within user control because want use on multiple pages.

can please solution stop ddlproject_textchanged being fired when unit , discipline changed?

thanks in advance

andy

edit:

i've discovered might not ajaxmanager. control events seem getting fired every time page post back. have standard asp.net button on click not databind of checkboxes, processes selected values in user control. it's external user control contains combo boxes.

combobox structure:

<telerik:radcombobox id="ddlunit" runat="server" checkboxes="true" enablecheckallitemscheckbox="true"     maxheight="450px" width="300px" datatextfield="value" datavaluefield="key" label="unit:"     labelcssclass="headerlabel" dropdownwidth="600px" height="400px"    autopostback="true" ontextchanged="ddlunit_textchanged"> </telerik:radcombobox> 

textchanged event

protected void ddldiscipline_textchanged(object sender, eventargs e)         {             ctrmdataservice ctrmds = new ctrmdataservice();              this.ddldoctype.datasource = ctrmds.getdocumenttypesforprojectsdisciplineandunit(getselectedprojects(),                                                                                               getselecteddisciplines(),                                                                                               getselectedunits(),                                                                                               loggedonuser.id);             this.ddldoctype.databind();         } 

i've been informed telerik bug , has been passed on development team.

not working answer explains why i'm having problems.