Intermittent issues were our Website pages fail to load and admin site very slow

Hopefully someone can help out with the following issues listed below that have recently started to occur.

We have two websites occasionsemporium.co.uk and charmsupplies.co.uk that up until a few weeks ago have been running just fine, they are both on version 1.3.9h ( not upgraded yet due to them being heavily modified :no: ), they are using separate databases and have had not been modified for a long time.

They are hosted with Hostpapa who assure me that they have not made any changes to our server settings and can not see any issues from their end.

Please note these are all new problems that started a few weeks ago and are intermittent in nature, the issues are:-

• Website pages are intermittently very slow to load
• Admin is painfully slow
• Duplicate orders
• Orders with missing product purchase info
• Missing orders even though we receive a payment
• Install SQL Patches in Admin not uploading

Server info
Server Host: hp195.hostpapa.com (69.90.160.170) Database Host: localhost (127.0.0.1)
Server OS: Linux 3.10.0-427.10.1.lve1.4.9.el7.x86_64 Database: MySQL 5.6.29
Server Date: 26/05/2016 13:18:07 Database Date: 26/05/2016 13:18:06
HTTP Server: Apache
PHP Version: 5.5.35 (Zend: 2.5.0) PHP Memory Limit: 128M PHP Safe Mode: Off
PHP File Uploads: On Max Size: 64M POST Max Size: 64M
Database Data Size: 511,276 kB Database Index Size: 10,249 kB

Hope someone can help :smartalec:

Adam

This post isn't going to help, but to state the "obvious":

Zen Cart 1.3.9h + PHP 5.5.35 = Disaster-waiting-to-happen

Thank you for taking the time to reply, that makes sense to me, I will speak to my Host and see if I can run it on version 5.3, if not I suppose I will be plagued with problems until I upgrade.