Normal
When you say you have the two drives linked via usb, do you mean they're plugged into each other in series? If so, have you tried plugging each into its own usb port? Also, using the LAV filters is a good way to go. I have 5 drives in a server with over 1300 mkv file movies and they all play without any problems using MP 1.3alpha and the default LAV filters.
