Tvheadend

Hi there!
It's my first post here and I would like to thank everyone who is involved in the development of tvheadend.
This is my issue:
In my setup I have 3 lnbs
LNB1 port 0 (Astra 19,2)
LNB2 port 1 (Hotbird 13)
LNB3 port 2 (Astra 28,2)
and my satellite card is a Twinhan DVB-S2 (Skystar HD 2)

I can scan both Horizontal and Vertical freqs on Astra 19,2 and 28,2 but on Hotbird only the vertical ones.
The lnb is working fine because I have tested it in my windows installation.

Is there any suggestion of what causes this? The problem drives me insane

Thanks