Documents to Go sync with PC?

Hello! This enTourage help document - "How to: Synchronize Docs to Go from your Pocket eDGe to Your PC" - reads like I should be able to sync between my PE and my PC over USB. However, when I go through setup on my PC for DocsToGo, it tells me I have to upgrade to the full version before it will set up a sync partnership. When I try to purchase the full version, it tells me there isn't an upgrade path for my current DocsToGo serial number. What am I doing wrong?

Thank you,
Jan

Update: Apparently the USB connection to my PC had disconnected when the PE went to sleep. Once I woke the PE up and reconnected, I was able to continue in the DocsToGo desktop wizard.