Hi Mathieu,

Thank you for reporting this issue! I verified the bug report and set its status to Unplanned.

Until the problem gets fixed, you can use one of the following solutions:

• Hide the ComboBoxItem with a CSS style:
  
  

              <style>
                  .hiddenItem  { display: none; }
              </style>
              <telerik:RadDropDownList runat="server" ID="ddl_example" Width="95%">
                  <Items>
                      <telerik:DropDownListItem Text="-" Value="-1" />
                      <telerik:DropDownListItem Text="Item 1" Value="1" />
                      <telerik:DropDownListItem Text="Item 2" Value="2" />
                      <telerik:DropDownListItem CssClass="hiddenItem" Text="Item 3" Value="3"/>
                      <telerik:DropDownListItem Text="Item 4" Value="4" />
                  </Items>
              </telerik:RadDropDownList>

  
  
  
• Replace the DropDownList with RadComboBox: 
  
  

              <telerik:RadComboBox runat="server" ID="ddl_example" Width="95%">
                  <Items>
                      <telerik:RadComboBoxItem Text="-" Value="-1" />
                      <telerik:RadComboBoxItem Text="Item 1" Value="1" />
                      <telerik:RadComboBoxItem Text="Item 2" Value="2" />
                      <telerik:RadComboBoxItem Visible="false" Text="Item 3" Value="3"/>
                      <telerik:RadComboBoxItem Text="Item 4" Value="4" />
                  </Items>
              </telerik:RadComboBox>

As a small token of gratitude for reporting the issue, I updated your Telerik points.

Regards,
Rumen
Progress Telerik