TV cards are still really poorly support on linux, tis a shame!
Really? I've been running Mythtv for almost three years now and have just upgraded to version 0.22. I've used a mixture of tuners over the years, currently have a Hauppage Nova-T 500 twin DVB-T PCI card and also a Nova-S DVB-S card. Never really had an issue with drivers and there are a lot of cards supported in the kernel these days without having to download and compile video4linux.
http://www.linuxtv.org/wiki/index.php/Main_Page
I've just bought a Technotrend S2-3200 to view CH4 HD with and have also got support working for pay tv via a OK Omnikey USB card reader.
Your card (a HVR-1100?) is basically a HVR-1300 without the MPEG encoder, the HVR-1110 has confusingly got a different chipset, so you need to look at this page -
http://www.linuxtv.org/wiki/index.php/Hauppauge_WinTV-HVR-1300.
I had a HVR-1300 about two years ago in my Mythtv box and it worked fine for DVB-T, I had to download and compile the v4l source but I think the driver is included in kernel >= 2.6.12.
I had an issue where it would try and load the wrong driver/module, IIRC it was trying to load cx88_blackbird, I remember adding this to the /etc/modprobe.d/blacklisted_modules file to prevent it from loading.
If you are still having issues perhaps you could post the output of "lsmod"? also the last few lines of dmesg after a fresh reboot (tv cards are usually initialised at the end of startup so should be close to the end of the dmesg output).
Not sure where the w_scan command is from as it is usually dvbscan or scan, you may also have some files which will help with the scan process under /usr/share/doc/linuxtv-dvb-apps-1.1.0/examples/scan/dvb-t/
Using a file which matches your location:
scan /usr/share/doc/linuxtv-dvb-apps-1.1.0/examples/scan/dvb-t/uk-Midhurst > channels.conf
Regards
Dave K.
PS. I would take the signal levels reported with a pinch of salt as they may not be entirely accurate.
