problem with vlan interfaces tagging/untagging in a simulated switch box

[saeedeh motlagh]

i think i have similar problem too. you want to have tagged and
untagged traffic at the same time on the trunk port, right?
in your topology the vlans and trunk port are bridged and the tagged
traffic is passed through the trunk port and every thing works fine.
then  when you want to have the untagged traffic on the trunk port,
you bridge an interface with trunk port directly. after that all the
traffic which is received on the trunk port, are sent to this
interface and vlans receive no packet.

                 eth0 -+
                            |
                 eth1 -+ --- bridge1 --- vlan9 --+-- eth4  -----
                                                                              |
                eth2 -+ --- bridge2 --- vlan8 --+ --------+
                                                                               |
                eth3 -+ ------------ bridge3 ----------------+

please let me know if i understand what you exactly mean.
yours,