asterisk users - Apr 2005 - proper 2-card ISDN modem.conf configuration?

I'm trying to configure an asterisk box with two cards.

Incoming calls are working fine with two ISDN cards, however, I am able 
to make outgoing calls only through the first card.

exten => _0.,1,Dial(Modem/g1:${EXTEN:1})
exten => _9.,1,Dial(Modem/g2:${EXTEN:1})

If I try to use the second card, asterisk says that the line is busy 
(which isn't true).

So I thought that maybe my modem.conf is wrong?

Could you paste your modem.conf here, if you are using more than one 
ISDN card?

Below my modem.conf:

[interfaces]

context=remote
driver=i4l
language=de
type=i4l
dialtype=tone
mode=immediate
dtmfmode=both

group=1
msn=27229933
incomingmsn=*
device => /dev/ttyI0
device => /dev/ttyI1

group=2
msn=624
incomingmsn=*
device => /dev/ttyI2
device => /dev/ttyI3



Tomek