Tvheadend

Hi,

I'm using Tvheadend (2.12, latest?), XBMC (Eden with PVR) and a Geniatech t238b to try and watch live TV on a Ubuntu machine running 11.10.

I have watched live TV through XBMC so it all talks to each other quite nicely (haven't tried any recording yet). However I am only getting a small subset of channels.

I am based in South London in an apartment which has a communal aerial, my TV has a built in freeview tuner and sees everything fine. I am using this list of muxes (which appear to be up to date):
http://linuxtv.org/hg/dvb-apps/file/0c9932885287/util/scan/dvb-t/uk-CrystalPalace

However Tvheadend only "sees" the mux on line 6 (Mux 2 (D3&4) I think) and when I delete it and add it manually pops up instantly with all services and a 100% signal strength. Briefly it connected to the one on line 9 (Multiplex C (Arqiva A) I think) but then I started deleting all the muxes and re-adding them by hand to see if that helped and it has not connected to that one since.

I left it overnight, with idle scan on and monitor signal strength on and this morning it was saying 0% signal strength on all 6 muxes.

Am I missing something? What can I try to do to troubleshoot the problem? Is there a way that Tvheadend can just "sniff" the information like the TV appears to (i.e. just work its way through every frequency and settle on a strong one).

Thanks in advance.