T-shaped bridge inhibits traffic insertion

Hello,

I have built several bridges that are connected to a ring via wlan devices. To avoid the problems mentioned in FAQs i use tap-tunnels over the wlan links. So my bridge looks like this:

          eth0
           |

tap0 ---- br0 ----- tap1

When traffic is going from tap0 to tap1 it is almost impossible for eth0 to insert traffic. Is there some priority concerning the traffic on an interface?

Is there a way to influence this behavior?

These are my settings:
[root@swa root]# brctl show br0

bridge name     bridge id               STP enabled     interfaces
br0             0014.0000cb2610f0       yes             eth0

tap0 tap1
[root@swa root]# brctl showstp br0
br0
bridge id 0014.0000cb2610f0
designated root 000a.0000cb260d44

 root port                 3                    path cost   100
 max age                  20.00                 bridge max age    20.00
 hello time                2.00                 bridge hello time     2.00
 forward delay            15.00                 bridge forward delay 
 15.00
 ageing time             300.00                 gc interval     4.00
 hello timer               0.00                 tcn timer     0.00
 topology change timer     0.00                 gc timer     0.61

flags

eth0 (1)

 port id                8001                    state  forwarding
 designated root        000a.0000cb260d44       path cost    10
 designated bridge      0014.0000cb2610f0       message age timer     0.00
 designated port        8001                    forward delay timer 

0.00
designated cost 100 hold timer 0.00
flags

tap0 (2)

 port id                8002                    state  forwarding
 designated root        000a.0000cb260d44       path cost   100
 designated bridge      0014.0000cb2610f0       message age timer     0.00
 designated port        8002                    forward delay timer 

0.00
designated cost 100 hold timer 0.00
flags

tap1 (3)

 port id                8003                    state  forwarding
 designated root        000a.0000cb260d44       path cost   100
 designated bridge      000a.0000cb260d44       message age timer     1.36
 designated port        8003                    forward delay timer 

0.00
designated cost 0 hold timer 0.00
flags

TIA

Bernhard 'Gustl' Bauer