css first and last doesn't work in selenium rc

I have a query:

x= sel.is_element_present("css=div#result form[class*='result']:last")

gives me false, but this:

    <td>storeElementPresent</td>
<td>css=div#result form[class*='result']:last</td>
<td>selFlightsFormCurre开发者_如何学Gont</td>

gives me true.

Is there any bug with it?

You might want to consider using an XPath selector to get your first and last items. I've found XPath to be a bit more flexible than CSS.