Tucows certificate is trusted by GeoTrust. In Java 1.3.x and older the standard java cartcerts file doesn't include GeoTrust root certificates and therefore Parallels H-Sphere returns 'Connect error, untrusted server cert chain' when trying to connect to the merchant gateway. That's why GeoTrust certificates should be imported into cacerts file.
So, if you have Java 1.3 and older, you have the following solutions:
A. If you have got the default java cacerts file and you have never changed it, you can simply replace it with the cacerts file offered by Parallels:
B. If you need to keep your cacerts file, use the keytool feature available in the standard Java installation in the Tucows manual (SSL notes).
C. Upgrade Java to 1.4 by following our documentation in Sysadmin Guide.
Note: If your certificate is already imported into cacerts, but Java still generates 'Connect error, untrusted server cert chain', please check the connection to your payment server from your control panel server by running the following command from the control panel server console to check connection:
telnet [server.name] [port]
Important: To provide non US cardholders CC processing, disable AVS check-up in the merchant gateway configuration.
CVV (Card Verification Value). To enable fraud protection using CVV, enable and configure CVV support in your Tucows account. More on CVV credit card verification.