<form action="[[~[[+landing]]]]" method="[[+method]]">
<fieldset>
<input type="text" name="[[+searchIndex]]" id="[[+searchIndex]]" value="[[+searchValue]]" />
<input type="hidden" name="id" value="[[+landing]]" />
<input type="submit" value="[[%sisea.search? &namespace=`sisea` &topic=`default`]]" id="searchButton" class="bttn" />
</fieldset>
</form>
☆ A M B ☆
<form action="[[~50]]" method="[[+method]]">
Ok, what happens if you use
<form action="[[~50]]" method="[[+method]]">
☆ A M B ☆
action="http : //mysite.com/search-results.html"
Try making the action attribute be the actual URL to the landing page.
action="http : //mysite.com/search-results.html"
☆ A M B ☆
That means the URL to your search-result page wasn't correct, you're getting the default "not found" page (your home page, resource #1).
☆ A M B ☆
It may have something to do with your "container_suffix" setting. If a resource is a container, it's given a different suffix (by default / rather than .html).