When a wired sync fails for a legacy device, the conventional wisdom is to clear the browser cache and try again. A bigger hammer is to clear the browser cache AND remove/reinstall the desktop sync program.
If that doesn't work and nobody else chimes in here, you're probably going to have to open a support ticket.
an update - it looks like i had a bad route somewhere on my device that i was trying to sync. i went and deleted the routes i was trying to uploaded and it sync'd fine
