MS Office communicator 2007 r2 - issues with incoming video calls

[aromes]

Hi,

We all use  MS Office communicator 2007 r2 on our small network (approx 30 users). I have no problem at all with outgoing video calls (I video call anyone on that same local network and everything works fast). But when the other users of that same network do video call me, I just see the sign of an up arrow that keeps moving (the usual sign that there is an upcoming call), but the video call window of the incoming call never displays. Eventually, the incoming call is dropped because I can't pick it up. Thanks for your help