cisco isdn vic 2 bri not using b2 channel

Hi,

I have 4 port vic channles and 3 (isdn 2s from Telstra Australia). I've configured the BRI interface as follows:

interface BRI0/0/0
 no ip address
 isdn switch-type basic-net3
 isdn point-to-point-setup
 isdn incoming-voice voice
 isdn static-tei 0
 trunk-group ALL_BRI
!
interface BRI0/0/1
 no ip address
 isdn switch-type basic-net3
 isdn point-to-point-setup
 isdn incoming-voice voice
 isdn static-tei 0
 trunk-group ALL_BRI
!
interface BRI0/1/0
 no ip address
 isdn switch-type basic-net3
 isdn point-to-point-setup
 isdn incoming-voice voice
 isdn static-tei 0
 trunk-group ALL_BRI
!
interface BRI0/1/1
 no ip address
 isdn switch-type basic-net3
 isdn point-to-point-setup
 isdn incoming-voice voice
 isdn static-tei 0
 trunk-group ALL_BRI
!

and i've configured the voice ports as follows.

voice-port 0/0/0
 compand-type a-law
 cptone AU
 timeouts interdigit 3
 timeouts call-disconnect 5
 timeouts wait-release 5
!
voice-port 0/0/1
 compand-type a-law
 cptone AU
 timeouts interdigit 3
 timeouts call-disconnect 5
 timeouts wait-release 5
!
voice-port 0/1/0
 compand-type a-law
 cptone AU
 timeouts interdigit 3
 timeouts call-disconnect 5
 timeouts wait-release 5
!
voice-port 0/1/1
 compand-type a-law
 cptone AU
 timeouts interdigit 3
 timeouts call-disconnect 5
 timeouts wait-release 5
!
!

I'm getting 3 out of my 6 possible lines and when after doing sh logging i realise only :1 channels are in use and :2 channel never gets used. I've a combination of more than 3 simultanious calls and it wouldn't handle it. Any ideas what i need to do here?

REgards
Huss