JSON.parse: unexpected character when receiving assoc array from PHP json_encode

UPDATE

So the JQuery.post() function receives valid JSON. I know the attribute "json" in the function call should already be enough to get the original array and .parseJSON() is not necessary. I guess that's why I get the syntax error when using this function.

But somehow I still can't access the array without the .parseJSON(). In fact, when I use typeof(data) it's still a string. I can write it to the console and it's still valid JSON.

How do I use my array (originally associated PHP array encoded once via json_encode()) as normal associated array in JavaScript?

ORIGINAL POST

I've been getting this syntax error for days and it's driving me crazy. I read a lot of posts and I know it must be a super simple thing I'm missing. Please help. Thanks in advance.

var institute = $.post("../libraries/load_content.php",
    {
        funct:   "getInstituteAddress",
        ins_name: "Institut für Informatik",
        ins_city: "Kiel"
    }, "json");
    institute.done(function(data) {
        alert(data);
        var ins_data = $.parseJSON(data); // <-- throws syntax error
        $("#street").empty().val(ins_data['ins_street']);
        $("#number").empty().val(ins_data['ins_number']);
        $("#postalcode").empty().val(ins_data['ins_postal_code']);
    }, "json");
    institute.fail(function(data) {
        console.log("Retrieving institute data failed. Returned:"+data);
    });

The JQuery.post() function calls a php script, which fetches the required data from the DB and returns an associative array with json_encode().

This works fine till this point.

{"ins_name": "Institut für Informatik",
 "ins_street": "HRSl",
 "ins_number": "42",
 "ins_postal_code": "24118",
 "ins_city": "Kiel"}

Above I alert the returned String and the JSONLint validator tells me it's valid JSON.

So I copied the String directly into the parseJSON() call. Worked fine. Why not with the variable?

Here's what I tried:

• I often read about missing single/double quotes. No luck here. Added them in multiple variations acound the String.
• I also often read that the parseJSON function is not required in such environment. So I dropped the function call. The syntax error of course disappears, but the I can't read the JSON as normal array so the fields are just emptied.
• I tried replacing the .post() function by .ajax(), adding the missing arguments... with the same effect.
• I changed the dataType attributes to html or text. Again no luck.