PHP on IIS 6 w/MS SQL HELP!!

[idgaf]

Does anyone know why PHP might have intermittent connection problems to an MS SQL database?

PHP 4.3.9
WIN 2003 w/IIS 6

Sometimes the script will work fine but then for minutes at a time and for no aparent reason, the PHP script will yield:

Warning: mssql_pconnect(): Unable to connect to server: XBOX in C:\Siteroot\crm\data\main.php on line 7

The relevant code follows:

define("db_hostname", "XBOX");
define("db_database", "CRM_DEV");

function query() {
    $_conn = mssql_pconnect(db_hostname) or die(mssql_get_last_message());
    mssql_select_db(db_database, $_conn) or    die(mssql_get_last_message());
    $_rset = mssql_query(@func_get_arg(0), $_conn) or die(mssql_get_last_message());
    mssql_close($_conn) or die(mssql_get_last_message());
    return $_rset;
} 

Not even restarting MS SQL or IIS seems to fix the problem, it still errors out whenever it wants.