The error points to a driver error, 0x0000008e. It is not any more specific than that, there is no file reference.
I ran all the diagnostics. They come up clean. I tried stressing the connection with simultaneous priority read and writes to the external, recording a show to the internal, a show playing from external, and SA processing a show. Result - no problem.
The problem only occurs when media center is set to record to the external and DTB file watcher is on.
Media center record external, No DTB -- No Problem
Media center record internal, DTB engaged -- No Problem
Media center record external, DTB engaged -- Periodic BSODs that are more frequent with USB than FW800.