Ajax post fails after server move - php

Question

I'm encountering problems after moving my project management tool to a new server. There is a checkbox on the project list page which when enabled hides all project with the status of complete and writes an entry in the config table of the database (HIDE_COMPLETE_PROJECTS) and then reloads the project list page after the AJAX post is successful. However, after moving the site to another server, changes are made to the hange_hide_completed_status.php. database but the project list page does not reload, it seems that no response is being sent back from the server. Not sure if it makes a difference but my old server had php 5.2,17, the new one has 5.4 installed. Also the version of jquery is very old (1.4.4). I thought I might have a problem with compression, so disabled mod_deflate on the new server, but this didn't help. Interestingly if I call the php file change_hide_completed_status.php directly from the old site, I get non-printing characters and on the new site, firefox won't display the page due to a content encoding error. I think there is a problem with the server configuration/the content type but I can't get any closer.
Here is the code:
function changeStatus(checkboxStatus){
if (checkboxStatus.checked){
hide_status_value =1;
}else{
hide_status_value =0;
}
$.ajax({
type: 'POST',
data: {'hide_status':hide_status_value},
url: 'change_hide_completed_status.php',
cache:false,
success: function(response) {
window.location.reload(true);
}
});
}
<?php
include_once ("/var/www/sdtm/etc/config.php");
$status = $REQUEST_DATA['hide_status'];
$d = new PhPagaDbData;
$fields = array('HIDE_COMPLETE_PROJECTS' => $status);
$key = 'HIDE_COMPLETE_PROJECTS';
$fields = array('cfg_value' => $status);
$r = $d->update('config', $fields, 'cfg_key = ?', $key);
exit;
?>
HTTP response old server:
POST /sdtm/change_hide_completed_status.php HTTP/1.1
Host: mccosh.de
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:34.0) Gecko/20100101 Firefox/34.0
Accept: */*
Accept-Language: de,en-US;q=0.7,en;q=0.3
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Referer: http://mccosh.de/sdtm/projects.php
Content-Length: 13
Cookie: PHPSESSID=d2b013669f1268af1cf516e60ae20c75
Authorization: Basic c2VjcmV0OnNlY3JldA==
Connection: keep-alive
Pragma: no-cache
Cache-Control: no-cache
hide_status=0
HTTP/1.1 200 OK
Date: Tue, 30 Dec 2014 11:04:13 GMT
Server: Apache
X-Powered-By: PHP/5.2.17
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 220
Keep-Alive: timeout=5, max=8
Connection: Keep-Alive
Content-Type: text/html; charset=iso-8859-1
HTTP response new server:
http://192.168.148.180:12323/change_hide_completed_status.php
POST /change_hide_completed_status.php HTTP/1.1
Host: 192.168.148.180:12323
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:34.0) Gecko/20100101 Firefox/34.0
Accept: */*
Accept-Language: de,en-US;q=0.7,en;q=0.3
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Referer: http://192.168.148.180:12323/projects.php
Content-Length: 13
Cookie: PHPSESSID=4pj4md762cm2n1efqm5kljuse2; shellInABox=942508454:111011010
Connection: keep-alive
Pragma: no-cache
Cache-Control: no-cache
hide_status=0
HTTP/1.1 200 OK
Date: Tue, 30 Dec 2014 10:39:16 GMT
Server: Apache/2.2.22 (Debian)
X-Powered-By: PHP/5.4.4-14+deb7u5
Content-Encoding: gzip
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Length: 23
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive
Content-Type: text/html; charset=iso-8859-1

Answer 1

So now I am feeling silly: the application uses it's own gzip compression which was screwing everything up. After disabling this, everything was fine.