I'm in the same boat. Since I upgraded to Mavericks, my VHS to DVD application says my iMac has a USB 1.0 connection and won't boot. Impossible, All the intel iMacs are USB 2.0.
So what are we to do?
Go with some other companies product? I'm not going to degrade my system. Why did the installation of Mavericks make Roxio's Easy VHS to DVD inoperable?