Multiple UPnP Servers on same interface/ip address

[KoS]

Hi

i am trying different upnp servers on the same host (= same interface and same IP address). should that work cleanly or is it supposed to create problems? at lest all upnp server have to listen on udp port 1900 ? i am expierncing strange problems as not all upnp servers are always listed on the control points... some times there is only one, sometimes there are three etc... (testing minim, twonky and logitechmediacenter (aka squeezecenter) together).

greets
KoS