Paystation Module Fail - "Paystation returned with the following error:"

Hi,

I am having issues with the Paystation Module 1.5.3. After correctly installing and setting up the module I receive the same error with all attempted payment transactions.

When "Confirm Order" is selected on the final checkout page (Page 3 of 3) I am redirected back to the Payment Information Page (Page 2 of 3) with the error "Paystation returned with the following error:". No error message is shown.

Running Zen Cart 1.5.1 but Paystation suggested I try their new 1.5.3 module.

This is on my local development server XAMPP 1.8.2 PHP V5.4.19/MySql V 5.0.10

I have checked and confirmed that the configuration details are correct and that I can log in to the temp development account.

I have asked Paystation for help in solving this problem but perhaps there are some who have already found a solution.

Any help/pointers in the right direction would be greatly appreciated.