I tried a signal booster when i was having trouble with certain channels and on demand a while back, made no differance, I too had a good quailty splitter so wound up calling Rogers after all else failed, they replaced the splitter I had and boom, problem solved. Now I had 4 tv's all hooked up but only 3 were on boxes the other was just straight to the tv tuner.
No problems since. I'm not suggesting you call Rogers all I'm saying is sometimes the spliiters you buy don't seem to meet the requirements of Rogers cable in NB.
Hitachi 51 GWX 20B | Sony STRDE845 Receiver | Rogers NB 6208 PVR + 2500 | Proson V6 Speakers | 16 x 22 Basement HT