Tvheadend

Hello, I own QNAP412 and I plugged my MSI Mega Sky 580 to my NAS, sadly I have 0% signal in TVHeadend (0.6.3)
(downloaded from http://forum.qnap.com/viewtopic.php?p=236907)

I had to download and deploy dvb-usb-megasky-02.fw and place it so it was loaded properly
(downloaded from https://code.google.com/p/mediawrt/source/browse/#svn%2Ftrunk%2Ffirmware)

lsusb output:
Bus 001 Device 005: ID 0db0:5580 Micro Star International Mega Sky 580 DVB-T Tuner [M902x]

dmesg output:
[ 7652.400000] dvb-usb: found a 'MSI Mega Sky 580 DVB-T USB2.0' in warm state.
[ 7652.400000] dvb-usb: will pass the complete MPEG2 transport stream to the software demuxer.
[ 7652.400000] DVB: registering new adapter (MSI Mega Sky 580 DVB-T USB2.0)
[ 7652.460000] DVB: registering adapter 0 frontend 0 (Zarlink MT352 DVB-T)...
[ 7652.480000] Quantek QT1010 successfully identified.
[ 7652.490000] input: IR-receiver inside an USB DVB receiver as /class/input/input1
[ 7652.490000] dvb-usb: schedule remote query interval to 100 msecs.
[ 7652.490000] dvb-usb: MSI Mega Sky 580 DVB-T USB2.0 successfully initialized and connected.

In Web UI (Configuration/TV Adapters) after I select "Zarlink MT352 DVB-T" I see following info:
Device path: /dev/dvb/adapter0
Device name: Zarlink MT352 DVB-T
Host connection: USB (480 Mbit/s)
Frequency range: 174000 kHz - 860000 kHz, in steps of 166 kHz
Status
Currently tuned to:
Services: 0
Muxes: 35
Muxes awaiting initial scan: 0
Signal Strength: 0%
Bit Error Rate: 0/s
Uncorrected Bit Errors: 0/s

I was able to add multiplexes from area, so system log contains:
Mar 08 23:55:40 dvb: Adapter "Zarlink MT352 DVB-T" Enabled
Mar 08 23:56:04 dvb: New mux "818,000 kHz" created by built-in configuration from "dvb-t_cz_All"
...
Mar 08 23:56:05 dvb: "/dev/dvb/adapter0" tuning to "818,000 kHz" -- Front configuration failed -- Bad file descriptor, frequency: 818000000
...

I also managed to install dvbsnoop utility on my NAS, output of ./dvbsnoop -s signal:
cycle: 1 d_time: 0.001 s Sig: 10399 SNR: 0 BER: 0 UBLK: 0 Stat: 0x00 []
cycle: 2 d_time: 0.034 s Sig: 10191 SNR: 0 BER: 0 UBLK: 0 Stat: 0x00 []
cycle: 3 d_time: 0.034 s Sig: 10335 SNR: 0 BER: 0 UBLK: 0 Stat: 0x00 []
cycle: 4 d_time: 0.035 s Sig: 10735 SNR: 0 BER: 0 UBLK: 0 Stat: 0x00 []
cycle: 5 d_time: 0.034 s Sig: 10591 SNR: 0 BER: 0 UBLK: 0 Stat: 0x00 []
cycle: 6 d_time: 0.034 s Sig: 10415 SNR: 0 BER: 0 UBLK: 0 Stat: 0x00 []
cycle: 7 d_time: 0.034 s Sig: 10703 SNR: 0 BER: 0 UBLK: 0 Stat: 0x00 []
...

Any ideas what can I do? When I moved my antenna around my flat I had Sig values from 5000-10000, but nothig else actually changed.