Ok...
Is the search results page cached? It CANNOT be cached.
If that’s working, then maybe I’m missing something. From what I understand, you have the search field in your template and wait... is it really like this:
[!Search? &FSF_showResults=`0` &FSF_landing=`43`!]
It should be:
[!FlexSearchForm?FSF_showResults=0&FSF_landing=43!]
*Note the snippet name.
That says use the FlexSearchForm snippet, but don’t show results here - only the form. When the form is submitted go to page 43.
Then on UNcached page 43 you should have in the content:
[!FlexSearchForm?FSF_showForm=0!]
if you don’t want the form showing up with the results (because it’s elsewhere in the template) or
[!FlexSearchForm!]
if you do want the form field there as well.
Hope that helps. Is there a URL we could look at? Sure it might not help a lot but it will make troubleshooters like myself feel better. Kind of like looking under the hood of your car when it breaks down... I’m no mechanic, but looking under the hood seems like the right thing to do.