I downloaded the latest version only to find out after starting the update that if the two year upgrade policy is up, you can no longer use your previous version. When I contacted Qdea here's what they said:

"When you purchase a license for Synchronize! Pro X, you have technical support and access to all versions of Synchronize! Pro X released within 2 years of your purchase at no additional charge.

Whatever problem you're having with the previous version of Synchronize! Pro X is a technical support issue, and we do not provide technical support more than two years after your purchase of a license, nor do we offer technical support for old versions of the software.

Best Regards,
Hugh Sontag
Qdea Technical Support"

S0 BEAWARE - If you try to update to the latest version and your past your upgrade period, then you'll loose the ability to use the version you own