We've got a web application that uses the Web Combo control.  We've got these little borders in between items in the combo box, as seen here in this image.  We've had some complaints about readability, and I was asked to remove this.

I can't seem to get rid of this border.  I figured I could change this with the RowStyle.BorderStyle property, like this:

ComboTextBox.DropDownLayout.RowStyle.BorderStyle = BorderStyle.None

This doesn't actually change anything, though.  The combo looks exactly the same.  Even if I get silly with it and set it to something like:

ComboTextBox.DropDownLayout.RowStyle.BorderStyle = BorderStyle.Solid

ComboTextBox.DropDownLayout.RowStyle.BorderWidth = New Unit("20px")

That still does not affect the border on the page.  It looks exactly the same.

I began experimenting with different settings, and I only found one property that affected the little borders between the items in the drop down.  It's this one:

ComboTextBox.DropDownLayout.RowAlternateStyle.BorderStyle = BorderStyle.None

When I set that, I do finally see the border go away on alternate rows:

I'm now worried that I might be up against some kind of bug in the control itself.  If AlternateRowStyle changes the border for every other item, shouldn't RowStyle change the style for all the rows?

Am I missing something?  Thanks!