I went over to my mother's to night to have a look at the 9150. If you switch it off and back on again you can change to another channel and it works fine. If you leave it on or go back to ITV1 for more than a minute it sticks again.
The 9300 in the other thread freezes on ITV1 and E4. This is what I put there:
The channels on Mux 2 are
Teletext Cars, 3 ITV1, 4 Channel 4, 6 ITV2, 10 ITV3, 13 Channel 4+1, 14 More4, 29 E4, 30 ITV4, 100 Teletext, 102 Teletext Holidays, 104 Teletext on 4, 728 Heart, 729 Radio Music Shop.
Maybe the freeze occurs on any of these channels.
I suspect some incompatible data has been introduced on this mux, maybe EPG, SIPSI, NIT or MHEG. It may be national or limited to a few transmitters.
Humax should be informed, they can determine what's wrong and pass that to broadcasters if necessary.