Does the device give any indication of initialization by the kernel?
1. Unplug the tuner from USB
2. do a ctrl-alt-F2 get up a terminal, login, then re-insert the tuner
3. run the command 'dmesg' look for output
If there is output identifying the tuner, then the kernel supports it, its just that LMCE does not have it's PCI-ID on file for PnP
If the tuner is properly identified, you can close your session in the terminal do a ctrl-D
After closing the session get back to LMCE by doing a ctrl-alt-F7
Run MythTV Setup from the computing menu, since this is a HD tuner, you want to select the tuner card as a "DVB" device, not the v4l or PVR or MPEG options. There should be an option to choose "DVB" if the card has been properly set up by the kernel, you should see the device in mythtv setup.
Since LMCE did not detect it, you will have to manually go through the rest of the setup, most of these prompts are self explanatory, however if you have some questions you can hit http://www.mythtv.org/wiki/index.php/Mythtv-setup
to help you out.
You will also need to hit http://schedulesdirect.org
and set up an account with your channels. This costs $20 a year US.
You will need to do this before completing the mythtv-setup. After you get a user name and PW, start mythtv-setup once more, enter this information when prompted, scan for your channels, etc. etc.
After completing setup, you will need to manually run 'mythfilldatabase' to populate your channels and such. This I usuallly do as root, but LMCE should do it for you going forward.
I had an issue not unlike this one with an older HD OTA (over the air) card. I have 2 of them in different boxes, and had to set them both up manually.
Hope this helps.
p.s. once you have confirmed you have everything working, get the PCI-ID's to the developers, so they can add it to the next build.
You can aquire this ID from running 'lscpi -vv | grep dvb' or just pipe it to less 'lspci -vv | less' and look for the device.