OnPhotonPlayerConnected not called back on non master clients?

Hi!

I have a strange behavior with OnPhotonPlayerConnected event.
The the client who created the room successfully receive OnPhotonPlayerConnected event, but the others who joined the room does not. The log's last few entries are:
Registered PhotonView ...
queueIncomingCommand() ...
OperationResponse 252: ReturnCode: 0.

On the master client the log's last few entries are:
Registered PhotonView ...
OnEvent: Event 253.

Where should I start to investigate the problem?
Thanks!