ASP.NET AJAX’s Combobox - Use HTML Tags in list entries

Question

I'm using the new Microsoft ASP.NET Ajax Combobox control.
But I want to use HTML-Tags for formatting in the DropDownlist. It renders to <ul> and <li> and not to <select> and <option>, so it should be possible.

My Control looks like this:

<act:ComboBox ID="cbxCompany" runat="server" Width="180" AutoCompleteMode="Append" CssClass="ComboBoxStyle" />

In the Code behind I do this:

cbxTyp.Items.Insert(0, New ListItem("<b>This is<b> formatted Text", "1"))
cbxTyp.Items.Insert(0, New ListItem("And now, an icon: <img src='icon.gif' />", "2"))

But the HTML-Code appears encoded.

Is it possible to use HTML tags? An attribute like "allowHTML" would be helpful.