I had problems connecting to MSSQL Server on port 1433 using PHP 5 on Windows 2003 Server.
Whenever i tried to connect to database on a remote/local server, php tried to connect using named pipes, instead of connecting on 1433. If i disable Named pipes on the Server, the connection fails.
As mentioned in one of the posts,from the \\Windows\\system32\\ folder, i copied and old ntwdblib.dll (dated 2000) to the php folder, and overwrote the newer file, dated 2005, that comes with php5 and suddenly, everything starts working. Php connects to MSSQL Database on port 1433 without problems.