We have been using a lot of updatepanels (yeah, I know there is a performance issue but that is a different post) and, as usual, it worked great on my computer but not so great at the customer site. What the panel does is to process a search request without the postback. At the customer site we saw the information being sent to the search engine and the data coming back, but it would never show the results.\
To make a long story short, after many network traces and a rather long call with Microsoft support the answer was actually rather simple. Our customer was using a master page based on the “BlueBand” master page. However there is a small issue with this master page. If you look at it you will see
<WebPartPages:SPWebPartManager runat=”server” />
<form runat=”server” onsubmit=”return _spFormOnSubmitWrapper();”>
Turns out that this is wrong. By moving the “WebPartPages:SPWebPartManager” tag underneath the “form” tag everything worked fine!