a caveat for audio routing with the Tascam US-1641

While setting up for recording with Reaper, I'd set up outputs 3&4 on the Tascam US-1641 as the channels to send to digital out, which is what I record. 1&2 are being used as headphone monitors, on which I can do Solo etc. Found that on restarting the machine, the digital outputs again go back to 1&2 by default. If the machine is put in hibernation, this does not happen. So, only if the machine is restarted, I have to go to the Tascam control panel and change the digital outs to 3&4.