Urgent help needed. Customer cannot check shipping and payment !!!

[signagen]

My size (signagenlabs.com) is based on Zen Cart Version 1.25. I have DHL shipping module and LinkPoint Payment System installed. They have been running good until recently when my host upgraded PHP to version 4.4.4. Right now customer cannot checkout shipping and payment. The checkout process freezes when customer clicks the button of "Check Out". No error message, it is just a blank page. I called ISP and asked them to check SSL setting. They replied the SSL was set correctly. When I remove DHL shipping module and activate Flat Rate Shipping Module. The checkout process goes to next step----"Checkout Payment". Then customer stuck in checkout payment (We use LinkPoint, it used to be working perfect). So can someone in here give me some hints on how to solve these problems? Help me out please. Many thanks.

Jeffrey

[Ajeh]

One post per question is all you need ... if you do not get a response in 24 hours ... add on to the post as either the person who could help you is not around ... or nobody knows what you are asking or talking about ...