Umbraco - postbacks caching problemm -

I am having problems with a page which I am developing in umbraco. I am quite new to this, so some guidance will be appreciated.

The problem seems to be linked to umbraco's cache pages.

I have a map of stock locksmith, a map of Australia in my case).

From this page the user can select an area to see the stockist inside that area.

I have a bigger search button in which the checkbox for some users should choose which area they want to search.

When I say 'Sydney' and press my search button, it's all right. This result gives me hope.

But ... if I'm going and click the Search button directly (again) - the search results will disappear.

It's talking about some strange caching like its umbraco, I've tried negligible with the caching setting within the developer area (i.e. 'cash period'), but any analog pattern that highlights the problem Have not seen

Oh, one more thing - its not to load the page load and PageInst Event (when it is received from the cache).

without choosing anything, you get a blank result, can it be that it is a control It's logic? As I saw, it returns empty results for the empty search query.