"DAE can't get audio from the disk fast enough. Your disk may be too slow or too fragmented. A firewire disk could be having trouble due to the extra firewire bandwidth or CPU load. 9073" error occurs on systems with no Firewire hard drives.
This error was not meant to indicate that ONLY Firewire drives would be the source of the error. In a future release it will be more generalized to cover all drive types.
One user reported this with a San Fiber Disk in a G5 (not compatible with PCI-X).