Same here. The Sat signal is perfect but Cable has a SNR of 29% and AGC of 9 - 10%, resulting in random glitching and stuttering.
I know my cable signal is not to blame, nor is it my gift as my DM800SE is perfect.
I've tried about 10 images so far and they all have the glitching and signal problems, the DVB-C tuners in these boxes is not good.