Based on the screenshot you could try our WebUI Studio 2009 R2 SP1 DetailView.aspx WebGrid sample. However, in order to replicate your scenario you will need to modify the MasterPage to DefaultMasterXHTML.master.

I did not see any issue with such configuration on the sample.

You could try installing our WebUI Studio 2009 R2 SP1 trial and try to see if the issue has been resolved using the latest component. You could inquiry our sales, sales@intersoftpt.com, regarding the cost of the new component.

I suspect that the issue is caused by XHTML doctype. WebDesktop 2.5 has limited compatibility with XHTML DocType. The support for XHTML has been enchanced in WebDesktop 3.

If you are not using XHTML doctype, do you mind creating a simple sample so we could replicate the issue in our environment?

Unfortunately, for the scenario to work without any issue you will need to use the temporary column in the datasource technique.

IF you would like to create the column dynamically, you will need to use the PrepareDataBinding server side event handler. Here is the snippet:

protected void Combo1_PrepareDataBinding(object sender, ISNet.WebUI.WebCombo.DataSourceEventArgs e)
{
    WebComboColumn fullName = new WebComboColumn();
    fullName.BaseFieldName = "FullName";
    fullName.HeaderText = "Full name";
    fullName.Name = "FullName";
    fullName.Hidden = true;
    fullName.RenderOnHidden = true;
    Combo1.Columns.Add(fullName);

    WebComboColumn firstName = new WebComboColumn();
    firstName.BaseFieldName = "FirstName";
    firstName.HeaderText = "First Name";
    firstName.Name = "FirstName";
    firstName.Width = Unit.Pixel(150);
    Combo1.Columns.Add(firstName);

    WebComboColumn lastName = new WebComboColumn();
    lastName.BaseFieldName = "LastName";
    lastName.HeaderText = "Last Name";
    lastName.Name = "LastName";
    lastName.Width = Unit.Pixel(150);
    Combo1.Columns.Add(lastName);

    WebComboColumn age = new WebComboColumn();
    age.BaseFieldName = "Age";
    age.HeaderText = "Age";
    age.Name = "Age";
    age.Width = Unit.Pixel(50);
    Combo1.Columns.Add(age);

    WebComboColumn gender = new WebComboColumn();
    gender.BaseFieldName = "Gender";
    gender.HeaderText = "Gender";
    gender.Name = "Gender";
    gender.Width = Unit.Pixel(100);
    Combo1.Columns.Add(gender);
}

Templating has not been supported in the latest version of WebCombo. Currently integration between WebCombo and WebGrid is limited to WebCombo as an EditColumnType in the WebGrid.

Similar to the Maintaining scroll position walkthrough, in order to achieve this you will need to buffer the scrolltop position during onScroll client side event.

One of the simplest method would be using a cookie to buffer the value, as shown in this post. 

Attached is the simple sample used to demonstrate such scenario.

Since WebGrid still could not persist selef reference state after postback, in a self refrence scenario this method might fail to set the scrolltop position correctly. 

You will need to create a temporary column in your datasource before binding it to the WebCombo in order to achieve the result you wanted.

Attached is the sample that has already implement such scenario.