Advanced Search According to Parameters

I've got a Product Type applied to all of my Products, and I've enabled the "Advanced Search According to Parameters" (ASATP) in the module. It seems to work fine.

However, if the results for a given search (all "135cm" products for instance) spill over to multiple pages of search results, only the first page displays accurately filtered results. In this example, it would display "Results 1 - 30 of 120" 135cm products. As soon as I click on the next page of results, it ignores the 135cm filter and instead shows me "Results 31 - 60 of 187" (my entire inventory). When I click back to the previous results page, I'll now see "Results 1 - 30 of 187".

Bugfix:
This seems to be a bug in VirtueMart. You can fix it, by placing following code in show.browse.php at line 153, right after line with "$search_string .=...":

// Following provides support for advanced search by product type parameters
if (!empty($product_type_id)){
foreach($_REQUEST as $key => $value){
if (substr($key, 0,13) == "product_type_"){
$search_string .="&".$key."=".$value;
}
}
}
// --- bugfix end

It is working for me but, no with JoomSEF and Virtuemart plugin for Artio JoomSEF 2.1.0.