Pagination buttons with Greek characters in a URL query string fails in IE browsers

I'm using the following script in my website in order to create pagination "next-previous" functionality. It's a actually a Dreamweaver's code. The script uses the url to get some values and then it re-creates it. The result url in IE7 and IE8 contains non-readable characters and at the end the page does not work properly.

$queryString_met = "";
if (!empty($_SERVER['QUERY_STRING'])) {
    $params = explode("&", $_SERVER['QUERY_STRING']);
    $newParams = array();
    foreach ($params as $param) {
        if (
            stristr($param, "pageNum_met") == false
            && stristr($param, "totalRows_met") == false
        ) {
            array_push($newParams, $param);
        }
    }
    if (count($newParams) != 0) {
        $queryString_met = "&" . htmlentities(implode("&", $newParams));
    }
}
$queryString_met = sprintf("&totalRows_met=%d%s", $totalRows_met, $queryString_met);

Then when I display the data, I use:

<a href="<?php printf("%s?pageNum_met=%d%s", $currentPage, max(0, $pageNum_met - 1), $queryString_met); ?>"> << </a>

I don't understand which part of the code is responsible for this issue.

htmlentities(implode("&", $newParams));

htmlentities encodes all non-ASCII bytes in your string, usually needlessly, and, if you don't specify a charset argument, guessing your strings are in ISO-8859-1, which for Greek they definitely won't be. (Hopefully, you're using UTF-8 for everything in your site.)

Use htmlspecialchars instead, which will leave the non-ASCII characters alone and only encode what really does have to be encoded.

However, for this to be an issue at all, you would have to be using non-ASCII characters directly in your URL. This is really unreliable; don't. Unencoded non-ASCII characters are not valid in a URI at all; they must be %-encoded (eg. using urlencode). IRIs allow non-ASCII characters, which browsers can automatically UTF-8-encode and %-encode to turn them into URIs, but IE doesn't (always) do that.

[Also the script to process query string will fail for any value containing the targeted names, not just those beginning with them.]