Windows XP SP1
MSSQL 2000
Apache 2.0.44
PHP 4.3.1

Procedure definition:
CREATE PROCEDURE foo
  @filter VARCHAR(255)
AS
  SELECT id FROM bar WHERE baz LIKE @filter
GO;

Script:
<?php
$con = mssql_connect('localhost', $user, $password);
mssql_select_db($dbname);
$sp = mssql_init('foo');
mssql_bind($sp, '@filter', $filter, SQLVARCHAR);
$result = mssql_execute($sp);
print "[".$result."]\n"; // point A
while ($row = mssql_fetch_object($result)) {
  // do something with $row
}?>

If there are no records in bar that satisfy $filter, [1] is printed at point A, and then mssql_fetch_object (and other functions that expect a resource ID, e.g. mssql_next_result) fails.