I'm using the combobox control within an updatepanel on my page.  When loading the page the dropdown list button isn't displayed when accessing the page in IE7.  When the page is refreshed sometimes the button displays.  This works great in Firefox, no problems at all.

I've played around with the stylesheets a little bit but that hasn't helped very much.  I still see the same behavior.

Does anyone have any knowledge of the control to know why the button control would show this behavior?

Here is the control when I look at the view source of the page when the button of the combobox isn't displayed.  Funny thing is that this portion of the source looks identical when the button is displayed.  Code that is in bold is apparently the button I am talking about:

<div onchange="javascript:setTimeout('__doPostBack(\'C_QO_AddrValue\',\'\')', 0)" id="C_QO_AddrValue" style="display:inline;">
        <table id="C_QO_AddrValue_Table" cellspacing="0" cellpadding="0" border="0" style="border-width:0px;border-style:None;border-collapse:collapse;display:inline;position:relative;top:5px;">
            <tr>
                <td><input name="C_QO_AddrValue$TextBox" type="text" id="C_QO_AddrValue_TextBox" autocomplete="off" style="width:300px;" /></td><td><button id="C_QO_AddrValue_Button" type="button" style="visibility:hidden;"></button></td>
            </tr>
        </table><ul id="C_QO_AddrValue_OptionList" style="display:none;visibility:hidden;">
            <li>------</li><li>One Time Ship to Address</li>
        </ul><input type="hidden" name="C_QO_AddrValue$HiddenField" id="C_QO_AddrValue_HiddenField" value="0" />
    </div>

Please help.  I've been fighting this for about 3 days now.

Well after a week of fighting this thing I finally found the problem or at least the solution.  Our aspx pages include javascript from a third party vendor that are supposed to track stats like browsers used and things like that.  Well apparently there is a javascript error that is being repressed in that code that causes the combo box not to load correctly.  As soon as I removed the javascript in question from the page the combo boxes started working perfect in IE7.

Very strange problem that wasn't easy to locate, but finally have my solution.

I was having a very similar problem but the only scripts that were being run were auto generated scripts for AJAX.

To identify the problem I created a new page and added my components one at a time and test after each.

Eventually, I found that placing the dropdownlist control in a table for positioning stopped it from being displayed in IE6, 7 and 8 but would work fine in Firefox.

I had always wanted to re-write the page using CSS and <div> tags but was told there wasn't time. I now feel justified in saying "I told you so!".