I don't think this applies to me, since I'm not receiving any error.
Also your form is the same as mine. (the inputs are just reversed but that shouldn't matter). Although I will try to reverse them back.
"when you get the product search result error by applying the template in powerstore to a newly created page this is what you get. "
Not sure if this applies to you.
This is what I have (unmodified):
<form id="searchForm" method="get" action="Products_Results.php" >
<input name="Search" type="submit" value="Search" id="Search" alt="Search" />
<input type="text" name="S_ProductName" id="S_ProductName" />