Kenammo, Glad you like your D1. And thank you for posting your JRiver settings. I tweaked them on my own but I didn't know what I was doing and I'm still getting the popping/clicking.
However, today I received a used HRT II+, so I'll have a chance to compare the D1 (that I plan to send back) to it after I plug in your settings. I have great hopes for the HRT but it may very well pop like the D1 does w/ my current settings. I'll report back and let you know if your settings worked for me.
I'll be very interested in your findings with the HRT. Hopefully you'll soon be able to isolate the cause of your pop/click problems and get back to enjoying the music!