$.post, php, jQuery, and IE

$.post, php, jQuery, and IE

so this is a little bit specific. i am writing a php webpage which passes post data back asynchronously via jQuery to retrieve data from a database. my code works in every browser except for IE. as far as i can tell, when IE executes $.post(), it sets the $_POST[] variable such that isset() returns true, but there is nothing actually in the variable, whereas there is when i make the request in other browsers. any ideas how to get IE to play nice?

here is the relevant code:

client side javascript:

function RefreshTable()
{
var opBox = document.getElementById("opbox");
var testBox = document.getElementById("testbox");
if (opBox.selectedIndex == 0 || testBox.selectedIndex == 0)
{
return;
}
$.post("https://ontos4.ornl.gov/~z2p/server.php", {op: opBox.options[opBox.selectedIndex].value, test: testBox.options[testBox.selectedIndex].value} , function (data) {HandleJSON(data);}, "text");
}

function HandleJSON(data)
{
alert(data);
return;
}

server side php:

if (isset($_REQUEST['op']) && isset($_REQUEST['test']))
{
$op_test_return = array();
$dbconn = pg_pconnect("host=$SERVER user=$USERNAME password=$PASSWORD dbname=$DATABASE");
if ($dbconn)
{
$query = "SELECT * FROM main_list WHERE operation='" . $_REQUEST['op'] . "' AND test='" . $_REQUEST['test'] . "'";
if (!($op_test_return[] = pg_fetch_row(pg_query($query))))
{
echo "Network Error: Could not fetch data from database 1" . $_REQUEST['op'] . $_POST['op'];
return;
}