I am facing a problem while connecting to SQL instance remotely. It works fine on local server but when I try to connect remotely I have to specify port number. E.g. server\instance does not work rather I have to specify server\instance,2233. Browser service is running fine, Firewall is turned off and every other setting related to this fine. Below is the SQL server edition which is running on windows Server 2008 Standard:
Microsoft SQL Server 2005 - 9.00.4060.00 (X64) Mar 17 2011 13:06:52 Copyright (c) 1988-2005 Microsoft Corporation Developer Edition (64-bit) on Windows NT 6.0 (Build 6002: Service Pack 2)

Any suggesstions?