How many channels do you get when you scan?
I currently have 398 channels with no duplicates.
There are a few channels on 107MHz which are giving a lot of people problems, not just on the Q5, but on other receivers as well. I had to use a cable amplifier to get mine back. Luckily, they moved frequency again recently, so I no longer need the amp.
Perhaps your missing channels are on 107MHz in your area.