ssh into kvm-guests

[brizly vaan van Ulciputz <brizly@freenet.de>]

Hello all,

i don't know why i can not ssh-in into my kvm-guests from another
physical machine.

[all my machines/hosts/guests here are Fedora Core 13]
i have a kvm-host, running several bridged guests, and the host itself
is a openvpn-server, too.

the kvm-guests can vpn-connect, other clients in my network can
vpn-connect.

the kvm-host can ping each kvm-guest,
any network-client (in the same network) can ping the kvm-guests.

BUT i can not ssh-connect into my kvm-guests, neither 'normal' from
kvm-host nor from other vpn-clients.
Other vpn-client can connect each-other (open-vpn client-to-client is
enabled). And i can ssh-connect from kvm-guests to other normal guests -
but this is not the way i need.

i don't know where to look at any more. the kvm-host has a running br0,
with correct ip. eth0 is linked to br0. kvm-guests has correct ips set,
reaching internet and so on - all good.

only unknown point is that 
#brctl show 
gives me the information that br0 hast not STP enabled, but virbr0 has
(dont understand what STP is good for :-( ).

any ideas where to continue?

_____
Greetings
brizly