Tvheadend

Hi all,

I am getting the following error for most of the channels.
"No input detected"

I am using the DVB-C card below:

TerraTec Cinergy C DVB-C
[[http://linuxtv.org/wiki/index.php/TerraTec_Cinergy_C_DVB-C]]

on Ubuntu 11.04 Natty + XBMC + TVheadend

any clue what the problem could be

Thanks

Note: I can see some tv channel.