Unable to connect named instance even SQL Browser service is running

Hi,

I have a SQL Server with only named instance installed and it's using non-standard port number 1234. I can connect it from my client via SSM by entering server name as '<Servername>\INST1, 1234' or '<IPAddress>, 1234', but failed to connect it by '<Servername>\INST1' even the SQL Browser service is running on server and status is 'Active'. I checked everything and rebooted server, no luck. What else can I do?

Thanks,

Steven

starlee