If I remove the "option selected" line altogether, I get a blank in the combo before I click the arrow (the same if I leave the line in but put nothing between the >< , regardless of the value= attribute). I find that no matter whether the initial appearance is blank or contains some text, I always see it duplicated (highlighted) at the top of the dropdown when I click (even the blank line) but that's to indicate the current selection if the user doesn't choose something else. This by nature, but does not refer to your question about the duplicate highlighted item along with the same item being shown further down in the list.
What I did in some cases, is put some text in there that is not actually a searchable item, like "Select" for example, and leave my default value in the "option selected" line a preferred value from my list. This way the value is there but what you see is "Select." Then when you click the arrow, all the items in the list appear once, BUT, in keeping with the nature of the combo, the text "Select" is highlighted at the top in the drop list.
So, you either have a highlighted blank line at the top after you click, with nothing showing in the box before you click, or you have "Select" highlighted at the top after you click. But in the list of "true" items, nothing is duplicated. My workaround, to demonstrate, is as follows:
CODE
Valueless text:
<option selected value="<%=item%>"><%Response.write "Select"%></option>
Other option are: Blank
<option selected value="<%=item%>"></option>
OR
no option selected line at all
CODE
I don't think you can eliminate the highlighted duplication of what's already in the combo before you click. Ergo, do you want the combo to first appear blank, put some text in there like "Select item," OR, the 3rd option is to eliminate the "option selected" line completely; then, the first item in your recordset for the list will automatically appear (depending on how you were sorted) , but you still have the duplicate in the highlight, but in the highlight ONLY.
Did you follow all that?