iptables forward combined with bfifo doesnt work

I have 3 interfaces, 2 inteal(wlan0,wlan01 )and 1 exteal (eth1) and i want to configure traffic from eth1 ,so i use iptables to send all outgoing traffic from the inteal interfaces to eth1: So I use the following commands: iptables -t nat -A POSTROUTING --out-interface $IF -j MASQUERADE iptables -A FORWARD --in-interface $IFHU -j CLASSIFY --set-class 2:1 iptables -A FORWARD --in-interface $IFGU -j CLASSIFY --set-class 2:2

which basicaly work. So then i want to configure the traffic with tc rule and put priorities tc qdisc del dev $IF root #if is the eth1 tc qdisc add dev $IF root handle 1: tbf rate 1mbit burst 2750 limit 50000 tc qdisc add dev $IF parent 1: handle 2: prio
this automaticaly creates classes 2:1 2:2 and 2:3 with pfifofast scheduler .if i leave it like this it works perfectly..but i want to configure to use the bfifo scheduler to configure the bytes of every queue...so i add the following code: tc qdisc add dev $IF parent 2:1 handle 10 bfifo limit 60
tc qdisc add dev $IF parent 2:2 handle 20 bfifo limit 60
tc qdisc add dev $IF parent 2:3 handle 30 bfifo limit 60 so now the iptable forward has stoped working for some unknown reason...can anybody help?